Some years ago on a United flight from somewhere I forget, landing at IAD. We taxiied up to the gate and had to wait a few minutes for the gate crew. When they finally showed up, they actually bonked the jetbridge into the plane. Not hard enough to cause damage, I think, but enough to rock it. When they opened the doors, the FA came on the PA and said something like "Now that we've safely arrived in Washington Dulles, with no help from the gate crew, we'd like to welcome you..."