Chaplin stated that the suspect then put his gun to his head and pulled the trigger. Two other UPS employees were wounded, but have been released from the hospital, Cilia said. On Wednesday, Chaplin said there was no indication the shooting was terror-related but did not talk about a possible motive.
Gaut said employees were evacuated from the facility, which processes packages for delivery in the San Francisco area and has 850 workers.
Brent Andrew, from the Zuckerberg San Francisco General Hospital, says the emergency department had multiple admissions from theUPS shooting and "we expect more".
Police confirmed the shooting at the facility in the Potrero Hill neighborhood, about 2 1/2 miles from downtown San Francisco but didn't release further information.
Due to the confrontation between the police and the suspect and the shooting that took place, residents were warned to avoid the area.
After the shooting, UPS said the company wasn't immediately sure of the status of the survivors who were taken to the hospital. "We recognize the impact this shooting is having on the City and UPS".
The Bureau of Alcohol, Tobacco, Firearms and Explosives said on Twitter that they were responding to the shooting incident and providing report to San Francisco police.
At the scene, police seized two guns, including a Mac 10-style machine pistol, and a backpack filled with ammunition and three magazines, sources said.
Dozens of UPS employees were escorted from the facility under police guard, according to witness accounts. Two victims died at the scene of the shooting. The gunman fatally shot himself when confronted by police, authorities said. The gunman, Jimmy Lam, filed the grievance in March complaining that he was working excessive overtime, Joseph Cilia, an official with a Teamsters Union local that represents UPS workers in San Francisco, told The Associated Press.
"We all know the familiar faces of our local UPS drivers and delivery persons", Lee said.
"This is a tragedy that has touched many lives today", Assistant Police Chief Toney Chaplin said at the news conference.
Several people believed to be UPS employees stood on the rooftop parking area at the building with their hands raised, apparently to indicate they were not involved and needed assistance. "As they got on the bus, they were all ducking".
A witness says he heard at least five gunshots and saw UPS drivers running down the street screaming "shooter, shooter" after gunfire at a sprawling San Francisco package delivery warehouse.
- San Francisco Police (@SFPD) June 14, 2017#SFPD is asking people in the area to shelter in place.
The shooting prompted a large police response, according to officials.