The door plug that was blown out of an Alaska Airlines plane leaving Portland, Oregon en route to California last week apparently slipped out of position. The door plug was supposed to be held in place with four bolts, but those bolts are missing. They don't know if they are gone because of the accident or if they weren't installed. The door on the other side of the aircraft does have the bolts and they were not loose. The NTSB says it's too early to determine whether this is connected to loose bolts reportedly found on other Alaska Airlines and United Airlines planes.