MILWAUKEE (CBS 58) -- A Milwaukee County Transit System (MCTS) bus driver is facing charges in a deadly Christmas Day crash. 

According to a criminal complaint, Montrell Pharm fell asleep behind the wheel, causing a chain reaction crash near 47th and Villard. 

One person was killed, 79-year-old Robert Clemons. 

The complaint says during an interview, Pharm stated on Dec. 25, he worked from 9:49 a.m. to 12:22 a.m., with a "split" around 2-4 p.m. Pharm reportedly stated he had been working 14 hours days since Dec. 22. 

According to the complaint, Pharm told investigators he feels ashamed by what happened, but he was "looking straight ahead," and had a clear path, and that he was good.” The next thing he knew there was an impact.

According to investigators, this wasn't the first time Pharm fell asleep behind the wheel of a MCTS bus. 

Pharm is charged with homicide by negligent operation of a vehicle. 

Pharm is expected in court Feb. 20.