A man wearing a nylon stocking over his face got on a Metro bus at 3rd and Pike at roughly 6 p.m., according to police.
The man sat down and kept to himself until the bus reached the 6000 block of California Avenue SW, at which point police say he stood up, pulled out a handgun and began robbing passengers.
The gunman had already robbed at least three people when a group of men on the bus decided to do something. Police say the men tackled the robber and held him down until officers arrived.
Kelley Munro lives nearby and saw the end of the scary ordeal.
"We were sitting out on our balcony and all of the sudden the bus stopped in the street and the doors opened and people started pouring out," she said. "There was a lot of chaos. Some people were crying, others were going back on the bus to see if everyone was okay."
Police arrived soon after and took custody of the 19-year old. When they put him in the back of a police car, officers say he became violent and began kicking the plexiglass window.
"He was going crazy, screaming and yelling," Munro said. "They got it him in the car and he was kicking it and kicking it. It was pretty crazy."
Officers were able to get control of the man and move him to a prisoner-transport van. He was booked into King County Jail on suspicion of three counts of armed robbery.
Nobody was injured.