A verbal altercation between two men on a Blue Line light-rail train early Thursday escalated into a fight that ended with a fatal stabbing.

The men began sparring as the northbound train left the Mall of America station about 1 a.m. They exchanged words, which led to a physical fight. At one point one of the men pulled a knife and stabbed the other, said Metro Transit spokesman Howie Padilla.

The victim, identified later Thursday by the Hennepin County Medical Examiner's Office as Anthony Demetrius Watson, 45, of Minneapolis, was taken to HCMC in Minneapolis, where he died.

Metro Transit and Bloomington police responded to the scene and arrested the alleged assailant when the train stopped at the 28th Avenue Station, Padilla said.

The suspect, a 67-year-old man, was taken to the Hennepin County jail, where he was being held on probable cause murder. He has convictions for assault, criminal sexual conduct and disorderly conduct, according to court records.

Padilla said authorities will be reviewing surveillance video and speaking with witnesses to "piece together the puzzle."

The Hennepin County Sheriff's Office crime lab was called in to collect evidence, which will be forwarded to the county attorney for possible charges, Padilla said.

Tim Harlow