The day after a gunman killed three co-workers and then himself at a United Parcel Service facility in San Francisco, the victims' relatives, fellow employees and customers were mourning their deaths in both public and private.
On Wednesday night, the San Francisco medical examiner's office said the victims of the morning shooting in Potrero Hill were Benson Louie, 50; Wayne Chan, 56; and Michael Lefiti, 46, according to the Associated Press. Police identified the gunman as 38-year-old Jimmy Lam, who fatally shot himself in the head as police officers closed in.
Though it took hours for authorities to confirm who the victims were, word already had spread among their co-workers and family. By nightfall, a makeshift memorial in the city's Diamond Heights neighborhood was growing for delivery driver Lefiti.
"Around here, Mike isn't just a UPS guy, he's everyone's friend," UPS customer Barbara Branch told KBCW.
People left balloons, photos and a poster calling Lefiti a "gentle giant."
"He made you feel like you were a part of something," Judy Prejean told the station. "He was just an awesome person. I just want his family to know how much he was loved outside the family."
Lefiti, a Hercules resident, had attended Westmoor High School in Daly City, according to his Facebook page. He leaves behind a wife and five children.
Louie, 50, was a San Francisco native who went to George Washington High School and Roosevelt Middle School, according to several classmates on Facebook. Louie coached volleyball and was referred to as "Uncle Benson" by several of the people he coached on Facebook. He leaves behind a wife and two daughters.
The victims and the gunman were UPS drivers, said Kyle Peterson, a UPS spokesman. Chan had been with the delivery service for 28 years. Lefiti and Louie had been with the parcel service for 17 years.
Lam had worked at UPS for 18 years.
Grief counselors were on hand to support employees who returned to work Thursday at the San Bruno facility. Additional drivers and package handlers will be assisting employees through Saturday with orders, Peterson said.
UPS Chairman and CEO David Abney released a statement Thursday.
"The UPS family is deeply saddened by the tragic shooting in San Francisco on Wednesday, when four employees lost their lives," the statement read. "On behalf of all UPSers, I extend sincere condolences to the families of the deceased, and we pray for the speedy recovery of the injured employees. We are working to help our employees and the families of those impacted heal from this senseless tragedy, while also investigating the circumstances that led up to this event."
Lefiti, Louie and Chan were killed, and two others were wounded just before 9 a.m. when Lam opened fire inside the shipping facility off 17th and Utah streets. Lam and the others were in uniform and attending a daily meeting before making deliveries when gunfire erupted, according to a company spokesman.
When police arrived, they thought Lam was still inside and actively hunting co-workers. A special operations team went in after him and saw him turn his pistol on himself, police officials said. Two guns were recovered at the scene.
Police announced that the building was secured shortly after 10:30 a.m. Meanwhile, officers continued searching the premises for witnesses and additional victims.
"This was a frightful scene, and we just wanted to make sure someone wasn't so terrified that they were hiding and we didn't know they were inside the facility," Assistant Police Chief Toney Chaplin said.
The Bureau of Alcohol, Tobacco, Firearms and Explosives is assisting San Francisco investigators, said Alexandria Corneiro, a bureau spokeswoman. ATF is tracing the two guns found at the scene, she said.
The examination will track the weapons' history from its first sale at a distributor to the purchaser.
Authorities said the incident was not believed to be connected to terrorism. Police Chief William Scott told The Times that investigators were uncertain about Lam's motive.
Police were still conducting "a very active investigation on what may have caused this as well as [the gunman's] background," Scott said.
Lam, a resident of San Francisco, had filed a grievance in March complaining about excessive overtime, Joseph Cilia, a Teamsters Union official, told the Associated Press. The Teamsters local represents UPS workers in San Francisco.
Cilia said the gunman seemed to have targeted the three drivers who were shot and killed.
"I never knew Jimmy to not get along with people," Cilia said. "Jimmy wasn't a big complainer."
Lam had two previous arrests for driving under the influence of alcohol or drugs, said Max Szabo, a spokesman for the San Francisco district attorney's office.
In 2010, Lam pleaded no contest and was sentenced to three years' probation for DUI with a blood alcohol content level of .15 or greater and hit-and-run charges, he said.
Three years later, Lam was arrested again for DUI, Szabo said. This time, prosecutors filed a motion to revoke his probation. But he made a deal with the court and admitted to the probation violation, Szabo said.
Lam was sentenced to 10 days of community service, and his probation was extended a month, he said.
"This was a terrible tragedy that has left the city shaken and in search of answers," San Francisco District Attorney George Gascón said in a statement. "The individuals taken from us were a part of our community, and our hearts goes out to the families of the victims."
Steve Gaut, a UPS spokesman, said the building where the shooting occurred processes packages for delivery in the San Francisco area. The facility employs about 350 people, but it's unknown how many workers were inside at the time of the shooting, company officials said.
At an afternoon news conference Wednesday, Mayor Ed Lee reassured UPS workers and the families of victims that they would be taken care of.
"They are happy and hardworking people," Lee said. "We know them in every single neighborhood in the city."
In days to come, city officials will review the incident to determine whether any safety improvements can be made.
"Please keep UPSers in your prayers," said Rosemary Turner, president of UPS North California District, said counselors would be on hand to provide support.
For breaking California news, follow @JosephSerna on Twitter.
1:35 p.m.: This article was updated with comments from the ATF and the San Francisco district attorney's office.
11:45 a.m.: This article was updated with details on Lefiti and Louie, two of the shooting victims.
11:10 a.m.: This article was updated with information on the victims' work experience and details on UPS operations.
10:35 a.m.: This article was updated with a statement from UPS' chief executive.