Authorities say a man is in critical condition after a surgical team had to amputate his leg when he became pinned underneath a freight train in Philadelphia.

Police say the 46-year-old was hit at about 2:45 a.m. Wednesday on the tracks in the city's Bustleton section. It's unclear why the man was on the tracks.

Crews worked for about two hours to free him. Authorities say a surgical team from Einstein Medical Center was called in to amputate one of his legs. He remained conscious through the procedure.

The man's name has not been released.