Abstract: At 1:30 p.m. on April 22, 1992, Employee #1, an order selector, was walking through a door reading order forms when the overhead door, weighing about 140 lb, dropped about 4 to 5 feet without any activation. The door struck Employee #1's left shoulder and knocked him to the concrete floor. Fellow workers lifted the door from Employee #1 and assisted him in regaining consciousness. An ambulance took Employee #1 to UCD Medical Center. The roll-up door had been installed by Hawey Doors, Inc., and was checked for operation but was never used; it was always kept raised. Investigation showed the failure was due to misalignment when installed. The employer had no way of knowing of the condition.