WASHINGTON, D.C. (WDVM) — One person is dead and several others injured after a shooting at the Metro Potomac Avenue Station in Washington, D.C., on Wednesday morning that ended when passengers attacked and disarmed the shooter.

Metropolitan Police Department Executive Assistant Chief Ashan Benedict praised the “heroic actions of our citizens, our community, to disarm this shooter.”

But he added, “The fact that our citizens had to intervene with armed gunmen is disturbing to me.”

The violence began shortly after 9 a.m. when the man began brandishing a weapon and confronting passengers on a city bus in the southeast area of the city. The man pursued one of the passengers off the bus and shot them in the leg, Benedict said.

The man then went down the escalator of the nearby Potomac Avenue Metro stop, confronted someone who was buying a Metro pass and shot that person in the leg as well. Both victims were recovering in local hospitals. Nexstar’s WDVM reports that a third person suffered a hand injury.

Benedict characterized the shooter’s behavior as deeply erratic, saying, “He’s walking around brandishing a firearm and just randomly engaging people in confrontation. He’s clearly agitated about something.”

Officials said a Metro employee was shot and killed after trying to intervene. Benedict said later at a news conference that the worker’s “heroism had to be recognized.”

The gunman then attempted to board a Metro train and was apparently confronted and disarmed by the passengers. He exited the train car and was taken into custody by police officers, who recovered his weapon on the train tracks, Benedict said.

Neither the slain DC Metro employee’s identity nor that of the shooter has been released.

“I’m lucky to be alive,” said one witness, who didn’t want to be identified. He told Nexstar’s WDVM that the person who was shooting appeared to be firing at random and referred to himself as a “kill monger.”

Service on the Blue, Orange, and Silver lines was suspended between Federal Center SW and Minnesota Avenue/Benning Road.

This is a developing story; the Associated Press contributed to this report.