Police are questioning a man after a fatal stabbing on a Denver bus Tuesday.
Passengers say it all started with a fight--leading one man to stab another.
Sister station KCNC says police are not calling the man being questioned a suspect yet. They are still looking to heat from other witnesses.
The stabbing happened neat Colfax and Federal around 3 p.m. The victim survived long enough to be transported to the hospital, but later died.
The incident is now being investigated as a homicide.