RENTON, Wash. – The Thursday evening commute came to a violent end at the Renton Transit Center. Despite recent measures to beef up security, one man was stabbed during a melee over a cell phone.

A teen said it all started when some young people at the transit center took his cell phone and his father went to get it back.

KING

Despite recent measures to beef up security, one man was stabbed during a melee over a cell phone.

"He just went up to one of the kids that took my phone and tried to get it back," he said.

That's when, witnesses say, it got ugly fast.

"I was across the street and they came and told me that my dad and my grandpa were getting jumped, so I ran over here," he said. "I saw some guys arguing and yelling, and it looked like they were about to have a scuffle, and then I saw someone hit the ground."

The teen says the man who went down was his grandfather who had stepped in to help.

He wound up needing the help of medics after being stabbed twice in the chest.

The victim is in serious condition at Harborview Medical Center.

Renton Police say they have arrested three people in the stabbing, but there may be a fourth suspect still on the run.

The knife has not yet been located.