Investigators say a melee at Sylvester Park Wednesday afternoon took a violent turn when one man stabbed another and then ran away.
An angry crowd chased the man to a bus stop a few blocks away, and that's where the bus driver first got involved.
The driver, who does not want to be identified, saw the crowd charge up to her windshield and she immediately knew something was wrong.
Just seconds earlier, she said a man ran onto the bus and seemed to be in a big hurry.
"Then he grabbed his wallet and was really demanding that I go. 'Go go, go, go,' and I was like, 'Well, this doesn't seem right,'" she said.
The reason for the urgency became clear when the mob started surrounding the bus.
"They are yelling, 'We want him,' that he just stabbed someone," she said.
The driver had eleven innocent passengers on board and didn't want anyone to have to tangle with the mob, so she ordered the stabbing suspect out of the coach.
The man made his way to the back door with the pursuers hot on his heels.
"The individual exited the bus. He was taken across the street, beaten, and somewhere during that altercation he was stabbed," said Jason Hicks with the Washington State Patrol.
Hicks said the mob went too far and was acting more like vigilantes than good Samaritans.
"Once you have an individual on the ground and you start kicking them and punching them, it's a very likely chance that the individuals involved in that activity will at a minimum be charged with a simple assault," Hicks said.
For her part, the driver wishes the episode would have ended peacefully, but she couldn't risk the safety of her passengers.
"That makes me feel bad, you know. I just knew I didn't want any of my innocent passengers to be involved," she said.
The stabbing suspect remains at the hospital, but police say he'll be booked for attempted murder when he's released.
Investigators are now trying to track down the people in the crowd and hope to make more arrests in the case.
Anyone with information about either stabbing is asked to call the WSP tip line at (253) 538-3100.