The Los Angeles Sheriff's Department says a fist fight escalated into a stabbing on a northbound Metro Gold Line around 6:38 p.m. on Friday.
"That altercation resulted in one of the men being stabbed multiple times in the upper torso," said Metro Police Capt. Dan Cruz.
Randall Shelton was on the train at the Memorial Park Station and said he heard a commotion and people yelling.
"Everybody was yelling and running and doing their thing, basically got out of there," said Shelton.
Witnesses called 911 and gave a description of the suspect. Officers arrested 36-year-old Jose Paul Vasquez Flores and recovered a knife with blood stains in his pocket. He was treated for injuries sustained during his arrest.
The victim, a 33-year-old Hispanic male, was taken to a nearby hospital. He underwent emergency surgery and was listed in critical but stable condition.
Flores has been booked for assault with a deadly weapon. His bail is set at $1 million. Service at the Gold Line continued operation Friday evening.
Last Friday, a 59-year-old passenger was fatally stabbed on the Red Line approaching the Vine Station in Hollywood. It was the first homicide in the Metro line's history.
Authorities arrested 33-year-old Gene Sim in connection to the Red Line incident on Tuesday. He is being held without bail, but has not been charged in the case.
If you have any information in either incident contact detectives at 323-563-5000, if you would like to remain anonymous call Crime Stoppers at 800-222-TIPS.