A UPS employee opened fire at one of the company's package delivery facilities in San Francisco on Wednesday, killing three co-workers and then himself as officers closed in and workers ran frantically into the streets, police and company officials said.
Two other United Parcel Service employees were wounded in the shooting that prompted a massive police response in an industrial neighborhood, Assistant Police Chief Toney Chaplin told reporters.
Officials, UPS employees and neighbors described chaos and panic as shots rang out during a morning meeting before drivers were sent on their delivery routes.
"They were all in rapid succession," Raymond Deng, a 30-year-old tech worker who lives across the street from the warehouse, said of the gunshots. "It was like tat, tat, tat, tat, tat, tat, tat."
Police arrived in minutes. Officers found wounded victims and pulled them to safety and then confronted the gunman, who was armed with an "assault pistol," Chaplin said.
"The suspect put the gun to his head and discharged the weapon," Chaplin said, adding that police have not determined a motive.
Mayor Ed Lee said authorities saved lives with a "very proactive response."
"It could have been worse," he said, "lives were saved today."
It was not immediately clear how many employees were at the facility, but UPS said the warehouse employs 350 people. The shooter and all the victims were employees, UPS said in a statement.
UPS driver Marvin Calderon told KNTV that he recognized the gunman as a fellow employee, but he did not know him personally.
"I just started running out like crazy, like I've never run before," Calderon told the TV station.
After the gunfire, auto shop owner Robert Kim said he saw "a mob of UPS drivers" running down the street screaming "shooter, shooter."
Deng watched from his window in the Potrero Hill section of San Francisco as workers fled the building shouting. He said another group of about 10 people gathered on the roof and held up their hands waving for help.
"I saw police officers go up from the ramp and then storm the buildings," he said. "It's crazy."
The shooting came the same day a gunman opened fire on Republican lawmakers at a congressional baseball practice, wounding U.S. Rep. Steve Scalise of Louisiana and several others.