OSHA Accident Investigation · Summary #732271
ERECTION PROCESS,UNSECURED,OVERLOADED,BRACING,TRUSS,ROOF,CONSTRUCTION,STRUCK BY,FALLING OBJECT
Event description
Six employees injured by falling wood trusses
Investigation abstract
On August 18, 1987, Employees #1 through #6 were involved in the erection of 67 to the ground. Employees #1 through #6 were injured, falling with the trusses. Contributing factors to the collapse may have been (a) that not less than 4 bund les of plywood (approximately 2, 800 lb each) were on the roof and trusses at on e time and as much as 4,496 lb was on the roof at the time of the collapse, (b) possible damage to the trusses while they were being hoisted by a 25 ft long spr eader, and (c) inadequate bracing of the trusses (no web plane or bottom chord p lane bracing) of the wood and masonry walls. ft 7 1/2 in. long wood trusses at the west end of a building. The trusses were s upported by a wood frame wall on the south side and a concrete block wall on the north side, both 20 ft high. To secure the trusses both for permanent structura l strength and for temporary bracing to prevent collapse, the contractor used si x rows of stay laths (2 by 4 by 12 ft long) on the top chord plane, sheeting on the sides as the trusses were put in place, and placement of plywood as the roof work progressed. Thirty-two trusses, which started falling from the west end, t ipped east with a domino effect, and buckled, forcing out both walls and falling
Victims (7)
-
#1 Non-hospitalized injury Age 29 M
- Nature of injury
- 20
- Part of body
- 16
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#2 Non-hospitalized injury Age 30 M
- Nature of injury
- 3
- Part of body
- 3
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#3 Non-hospitalized injury Age 29 M
- Nature of injury
- 12
- Part of body
- 17
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#4 Non-hospitalized injury Age 26 M
- Nature of injury
- 3
- Part of body
- 7
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#5 Hospitalized Age 38 M
- Nature of injury
- 12
- Part of body
- 3
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#6 Hospitalized Age 30 M
- Nature of injury
- 12
- Part of body
- 24
- Event type
- 5
- Source
- 8
- Occupation code
- 567
- Human factor
- 11
- Environmental factor
- 13
- Task assigned
- 1
-
#981 Degree 0 Age 0
- Nature of injury
- 0
- Part of body
- 0
- Event type
- 0
- Source
- 0
- Occupation code
- 0
- Human factor
- 0
- Environmental factor
- 0
- Task assigned
- 0
Codes shown verbatim from OSHA's accident-investigation database. A human-readable decoder is coming in a future release once the accident_lookup2 dictionary is loaded.