Hazard

Employees were exposed to the hazard of falling through a damaged roof.

Process

A longshoreman was removing spilled dry material from underneath a material transfer chute on a roof.

Activity at time of incident:

A maintenance worker was walking on a roof surface to access a material transfer chute to clean underneath it.

Incident Description

Setting:

Two scalehouses, connected to a marine terminal warehouse, are each equipped with a chute-conveyor system used for transferring dry bulk material, such as fertilizer and salt. The scalehouses are located at opposite ends of the warehouse, and the chutes are housed within each scalehouse at roof level. During transfer operations, some dry material occasionally spills out of openings in the chutes, and once every two or three weeks, a maintenance employee climbs up to the chutes to remove the spilled material and manually shovel it back into the chutes. The employee typically uses a ladder to access one scalehouse chute, then walks across the warehouse roof to access the other scalehouse chute. The warehouse roof is nearly flat, with a pitch less than 2.5 degrees.

Incident:

On the day of the incident, a maintenance employee had finished cleaning around one of the scalehouse chutes and was walking along the warehouse roof towards the other scalehouse chute when the warehouse roof caved in. The employee had stepped on a weakened section of the roof and died after falling 20 feet to the concrete floor below.

Relevant Factors:

The employer had a contract in place to repair the roof's leaks. Until the repair work was done, employees should not have been working on the roof. As a temporary measure, the employee should have worked on the first chute and then moved the ladder to the other side of the warehouse to gain access to the second chute rather than walk across the damaged warehouse roof to move between the two chutes.

Note: Although the use of a ladder to access both chutes would have been an acceptable temporary control measure until roof repairs were made, it is not a recommended long-term solution because it increases the employee's exposure to fall hazards by doubling the amount of time the employee spends on the ladder. The safer method of gaining access to the second chute is to walk across the broad, flat, structurally sound roof at a safe distance from the roof edge.

Applicable Standards and Control Measures

• 29 CFR 1917.111(a): Maintenance and load limits. "The structural integrity of docks, piers, wharves, terminals and working surfaces shall be maintained."

This hazard could be prevented if the employer had prohibited the employee from walking on the roof until repairs to the weakened section of the roof were completed. Additionally, the hazard could have been prevented if the employer had periodically inspected the roof to ensure that it was in good condition and capable of supporting the weight of the activities performed on its surface.