On September 12, 2025, two workers were buried alive in a 14-foot-deep trench in suburban Atlanta. The trench had no shoring, no shielding, and no sloping. It had been dug that morning for a sewer line installation. The soil was classified Type B by the competent person on paper — except no competent person was on-site when the excavation began, and no soil test had been performed. The walls collapsed without warning at 10:23 a.m. It took rescue teams seven hours to recover the bodies.
Those two workers were among 39 construction workers killed in trench collapses in 2025, according to OSHA's preliminary fatality data — the highest number in over a decade. Every single one of those deaths was preventable. Not theoretically preventable. Practically, straightforwardly preventable with equipment and procedures that have been standard practice for over forty years.
OSHA's excavation standard — 29 CFR 1926 Subpart P — was last substantively updated in 1989. The requirements are clear, well-understood, and not technically difficult to implement. Yet trench fatalities have increased 44% since 2020, and OSHA's trenching and excavation compliance directive remains one of the agency's most active enforcement programs.
This article covers the standard, the common violations that kill workers, and the specific steps to ensure every excavation on your jobsite is compliant.
The Numbers
According to OSHA and BLS data:
- 39 workers killed in trench collapses in 2025 (OSHA preliminary)
- 131 workers killed in trench collapses over the past four years (2022-2025)
- Average rescue time for a buried worker: 4-8 hours
- Survival rate for workers buried above the waist: approximately 50%
- Survival rate for workers buried above the head: approximately 10%
- Weight of soil: One cubic yard of soil weighs approximately 2,700 pounds. A worker buried in a collapsed trench has thousands of pounds of earth pressing on their chest, restricting breathing, and often causing crush syndrome
Safety note: A cubic yard of soil weighs as much as a small car. A trench collapse is not like being buried in sand at the beach. The pressure on the chest prevents breathing within minutes. Compressive asphyxia is the primary cause of death, and it can occur even when the worker's head remains above the soil line. There is no "minor" trench collapse.
The Standard: 29 CFR 1926 Subpart P
The excavation standard applies to all open excavations, including trenches (excavations that are deeper than they are wide). The requirements escalate with depth:
Excavations less than 5 feet deep
Protective systems are not required unless examination of the ground by a competent person identifies conditions that indicate a hazard of cave-in exists.
Excavations 5 to 20 feet deep
The employer must use one of the following protective systems:
1. Sloping — Cutting the walls of the excavation at an angle that prevents collapse. The required angle depends on soil type:
- Type A soil (stable rock, ceite): Maximum 53 degrees from horizontal (3/4:1 slope)
- Type B soil (silt, sandy loam, unstable rock): Maximum 45 degrees (1:1 slope)
- Type C soil (gravel, sand, soft clay, submerged soil): Maximum 34 degrees (1.5:1 slope)
2. Benching — Creating a series of horizontal steps in the trench wall. Not permitted for Type C soil.
3. Shoring — Using hydraulic, pneumatic, or timber shoring systems to brace the trench walls. Shoring must be designed by a registered professional engineer or conform to tabulated data from the manufacturer.
4. Shielding (trench boxes) — Using a steel or aluminum trench box that protects workers inside from a collapse. The shield must be certified by the manufacturer for the depth and conditions of use.
Excavations deeper than 20 feet
Protective systems must be designed by a registered professional engineer.
The Competent Person Requirement
The competent person requirement — 29 CFR 1926.650(b) — is the single most critical element of excavation safety, and its violation is the single most common factor in trench fatalities.
The standard requires that a competent person:
- Classify the soil before excavation begins, using at least one visual test and at least one manual test (thumb penetration, pocket penetrometer, torvane, etc.)
- Inspect the excavation daily before each shift, after rainstorms, and after any event that could affect the stability of the excavation
- Have the authority to remove workers from the excavation immediately when a hazardous condition is identified
- Be on-site whenever workers are in the excavation
In the Atlanta incident, no competent person inspected the trench before workers entered. In approximately 60% of trench fatality investigations, OSHA found either no competent person designated, the competent person not on-site, or the competent person lacking the training or authority to perform the role.
The Five Violations That Kill Workers
Analysis of OSHA trench fatality investigations from 2020-2025 reveals five violations that appear in virtually every case:
1. No protective system at all
In 78% of trench fatalities, there was no sloping, shoring, shielding, or benching in the excavation. The trench had vertical walls, and workers were inside.
This is not a judgment-call violation. A vertical-walled trench deeper than five feet with workers inside is always a violation of 29 CFR 1926.652(a)(1). There is no exception, no exemption, and no defense. The only question is whether OSHA classifies it as serious or willful.
2. No competent person
In 60% of trench fatalities, the competent person was either not designated, not trained, not on-site, or not performing inspections. The competent person requirement is the triggering mechanism for the entire excavation safety system. Without it, soil classification does not happen, protective systems are not selected, and inspections are not performed.
3. No means of egress
29 CFR 1926.651(c)(2) requires that a means of egress — a ladder, ramp, or stairway — be provided in trench excavations four feet or deeper, and that no worker be more than 25 feet of lateral travel from a means of egress.
In many trench fatality investigations, workers had to travel the entire length of the trench to reach a ladder, if one was provided at all. When the collapse occurred, they could not reach the exit.
4. Spoil piles too close to the edge
29 CFR 1926.651(j)(2) requires that excavated materials (spoil) be kept at least two feet from the edge of the excavation. Spoil piles placed at the edge add surcharge loading that increases the pressure on the trench walls and significantly increases the probability of collapse.
In numerous fatality cases, the excavator operator had been piling spoil directly at the trench edge because it was convenient for backfilling. That convenience contributed directly to the collapse.
5. Adjacent to structures or heavy equipment
Trenches dug adjacent to existing foundations, roadways, or heavy equipment staging areas face additional surcharge loads that Table B-1 of the standard does not account for. The competent person must evaluate these additional loads and adjust the protective system accordingly — often requiring engineering input.
Several fatalities have occurred when heavy equipment was positioned too close to the trench edge, adding dynamic loading that caused the wall to collapse inward.
Soil Classification: Why It Matters
Soil classification determines the required slope angle or the specifications for shoring and shielding. Getting it wrong — or skipping it entirely — is the upstream failure that makes everything downstream inadequate.
The standard defines four soil categories:
Stable rock: Natural solid mineral matter that can be excavated with vertical sides and remain intact while exposed. Rare in trench excavations.
Type A: Cohesive soils with an unconfined compressive strength of 1.5 tons per square foot (tsf) or greater. Examples: clay, silty clay, sandy clay, clay loam. Type A is the strongest soil category and allows the steepest slopes.
However, soil cannot be classified as Type A if it has been previously disturbed, if it is fissured, if it is subject to vibration from traffic or heavy equipment, or if the excavation is undermined by other excavations. These exceptions are frequently overlooked. Many soils that look like Type A on paper are actually Type B or C in practice because of one of these disqualifying conditions.
Type B: Cohesive soils with an unconfined compressive strength between 0.5 and 1.5 tsf. Examples: angular gravel, silt, sandy loam, and previously disturbed Type A soils. Type B is the most common classification in urban trench work because virtually all urban soil has been previously disturbed.
Type C: Cohesive soils with an unconfined compressive strength of 0.5 tsf or less, and all granular soils including gravel, sand, and loamy sand. Also includes any submerged soil or soil from which water is freely seeping. Type C requires the flattest slopes (34 degrees from horizontal) and does not permit benching.
Safety note: When in doubt, classify down. If you are not sure whether the soil is Type B or Type C, call it Type C and slope or shield accordingly. No one has ever died because a trench was over-protected. Thirty-nine people died last year because trenches were under-protected.
The Economics of Trench Safety
The cost objection to trench protection is mathematically indefensible. Here are the real numbers:
Cost of a trench box (rental):
- 8-foot steel trench box: $150-$300 per day
- 12-foot steel trench box: $250-$500 per day
- Typical rental for a two-week sewer installation: $2,100-$7,000
Cost of sloping:
- Additional excavation to create 1:1 slopes on a 10-foot-deep, 100-foot-long trench: approximately 300-400 additional cubic yards of excavation
- At $15-$25 per cubic yard: $4,500-$10,000
Cost of a trench fatality:
- Average OSHA penalty for trench fatality: $340,000 (FY2025 data, often willful)
- Workers' compensation death benefit: $250,000-$500,000 depending on state
- Wrongful death lawsuit: $2,000,000-$8,000,000
- Criminal prosecution: OSHA can refer willful violations resulting in death to DOJ for criminal prosecution. Penalties include up to six months in prison and $250,000 in fines for individuals. Several states have pursued manslaughter charges for trench fatalities.
- Business impact: Project delays, bonding issues, prequalification failures, reputation damage
A trench box costs $300 per day. A trench fatality costs $3-8 million and potentially prison time. There is no cost-benefit analysis that favors skipping protection.
A Competent Person Checklist for Every Excavation
Print this. Put it in every competent person's clipboard. Use it before any worker enters any excavation deeper than four feet.
Before excavation begins:
- Underground utilities located and marked (call 811 at least 48 hours before excavation)
- Surface encumbrances (trees, poles, signs, sidewalks) removed or supported
- Adjacent structures and their foundations evaluated for stability
- Soil type determined by at least one visual test and one manual test
- Protective system selected based on soil classification and depth
- Means of egress (ladder or ramp) planned — one within every 25 feet of lateral travel
- Spoil pile placement planned — minimum 2 feet from edge
Before workers enter:
- Protective system in place and inspected
- Means of egress in place
- Atmosphere tested if hazardous atmosphere is suspected (e.g., near landfills, fuel storage, sewers)
- Water accumulation controlled
- Adjacent traffic and equipment controlled
- Workers briefed on hazards, egress locations, and emergency procedures
During work:
- Competent person remains on-site
- Continuous monitoring for changes in soil condition, water seepage, cracking
- Re-inspection after any rain, vibration, or changed condition
- Workers remain within 25 feet of egress at all times
OSHA's Enforcement Posture on Trenching
OSHA has maintained a national emphasis program on trenching and excavation since 2022, and enforcement intensity increased again in FY2026. Key enforcement data:
- FY2025 trenching inspections: 1,847 (up 31% from FY2023)
- FY2025 trenching citations: 1,312 serious; 187 willful
- Average serious penalty: $14,800
- Average willful penalty: $142,000
- Fatality-related penalties: Average $340,000 per employer
OSHA has also increasingly used its authority under Section 13(a) of the OSH Act to seek federal court injunctions that shut down excavation operations immediately when imminent danger is found. In FY2025, OSHA obtained 14 such injunctions for trenching violations — the highest number in the agency's history.
For more on OSHA's overall enforcement priorities, see our breakdown of OSHA's top 10 construction citations.
The connection between the construction workforce shortage and trench safety is direct. When experienced workers are scarce, newer workers with less training end up in trenches supervised by foremen who may not have adequate excavation safety training. The shortage is a safety problem, not just a production problem.
Frequently Asked Questions
At what depth does OSHA require trench protection in construction?
OSHA requires protective systems — sloping, shoring, shielding, or benching — in all trench excavations five feet or deeper, unless the excavation is made entirely in stable rock. For excavations less than five feet deep, protective systems are required only when a competent person identifies cave-in hazards. For excavations deeper than 20 feet, protective systems must be designed by a registered professional engineer. These requirements are found in 29 CFR 1926.652(a).
What is a competent person for excavation safety under OSHA?
A competent person for excavation safety is defined by OSHA as someone who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees, and who has the authority to take prompt corrective measures to eliminate them. For excavations, this specifically includes the ability to classify soil, select appropriate protective systems, inspect the excavation before each shift and after any hazard-increasing event, and the authority to remove workers from the excavation immediately when hazardous conditions are found.
How many workers die in trench collapses each year?
OSHA's preliminary data reports 39 construction workers killed in trench collapses in 2025, the highest number in over a decade. Over the four-year period from 2022-2025, 131 workers died in trench collapses. The fatality rate has increased 44% since 2020. Virtually all trench fatalities are attributable to the absence of required protective systems — no shoring, shielding, or sloping was in place in 78% of fatal incidents.
What are the OSHA penalties for trench safety violations?
OSHA penalties for trenching violations are among the highest in construction enforcement. In FY2025, the average serious trenching citation was $14,800, while the average willful citation was $142,000. Fatality-related penalties averaged $340,000 per employer. OSHA can also seek federal court injunctions to shut down excavation operations immediately when imminent danger is found, and willful violations resulting in a worker death can be referred to the Department of Justice for criminal prosecution, carrying penalties of up to six months in prison and $250,000 in fines for individuals.
