Abstract: At approximately 7:59 a.m. on April 15, 1994, Employee #1 fell unconscious in a vault while painting a well head with paint and methyl ethyl ketone (MEK) solvent. The employee was working alone in the vault, which measured 4 ft 2 in. wide by 12 ft 6 in. long by 5 ft 9 in. deep. The hatch dimensions were 2 ft 8 in. by 2 ft 10 in. The employee was using a half-mask respirator with chemical cartridges for organic vapors. The employee had a paint roller and a paint bucket, but no safety belt or hoisting device for confined space work. No ventilation was provided for the employee. He had been working for approximately one hour before he was spotted by another general contractor employee. The employee who spotted him entered the vault to check on his condition before asking for help to rescue Employee #1. He re-entered the vault and pulled out Employee #1. Shortly thereafter, the South Gate Station 54 Fire Department arrived and administered first aid to Employee #1. He suffered a shoulder injury and an apparent oxygen deficiency exposure and chemical exposure. No confined space procedures were implemented for this project.