A semi truck carrying U. S. mail slammed into the Charles River on Saturday after jack-knifing off a 50-foot bridge in Massachusetts.

Remarkably, the driver no only survived this crash but was uninjured. He told fire rescue workers out of Weston, Massachusetts that he didn’t know how to swim, so when his cab half sank into the river, he moved to the trailer and waited for help. Fire rescue happened to be in the area removing snow from fire hydrants and were able to respond quickly, :

Weston Deputy Fire Chief Justin Woodside said firefighters were quick to respond because they were already out on the road in the area, shoveling hydrants from Friday’s snowfall.

“We were able to make an effective rescue,” Woodside said. “Our two members went in with suits and we got him and it took about maybe four minutes or so upon arrival.”

The man was taken to Brigham and Women’s Hospital in Boston to be evaluated but no injuries were reported, .

The drama wasn’t over after the driver was rescued however. Clean up took all day and closed Exit 39 to the Massachusetts turnpike for 10 hours. As crews raised the shattered trailer out of the water, it split in two, spilling packages and letters out into the murky water. Crews had been hoping that the majority of item could be rescued, but that is no longer the case. A U.S. postal inspector worked over the weekend to gather pieces of mail that were not recovered by clean up crews.

The cause of the crash is under investigation. If you’re in the Boston area and are waiting on some mail coming via the U.S. postal service, you might be waiting for a hell of a long time.