I worked at a place where a fork truck was being driven onto a trailer and at that precise moment the truck driver started to pull the trailer away because he thought that the trailer was empty. Anyway the fork truck came off the dock and landed in the parking lot, with the forks buried in the pavement. Good thing the fork truck driver had his seat belt on or he could have died. To stop it from happening again all drivers have to block their tires and give their keys to the dock personell.