Mr. Wong, who entered the campus with at least one loaded rifle, reportedly took other hostages at the Pathway House on Friday. The three who remained and the gunman were found dead just before 6 p.m. local time, Assistant Chief Chris Childs of the California Highway Patrol said on Friday.
Sheriff John Robertson of Napa County said at a news conference on Friday that a deputy and the gunman exchanged gunfire at some point, and that the gunman released hostages, though it was unclear how many.
Larry Kamer, a spokesman for the organization, told The New York Times shortly after the attack that Mr. Wong arrived at a going-away party for two staff members. “He was very calm,” Mr. Kamer said, noting that his description was based on the observations of his wife, Devereaux Smith, the nonprofit’s director of development and communications, who was in the room but managed to leave.
The future of Madison Hall, which housed the Pathway Home, has not been determined, according to the statement. For now, it remains closed as the investigation continues.
Pathway’s statement said that the board was “examining a range of options to continue the important mission” of the program: “helping the nation’s post-9/11 veterans with mental health services and wellness support.”
More immediately, a fund called the #3BraveWomenFund has been established through the Pathway Home’s website to benefit the families of Ms. Loeber and Drs. Gonzales and Golick, as well as in support of other mental health services for military veterans.
The Associated Press, citing Defense Department records, said Mr. Wong was an Army veteran who had served in Afghanistan, and the Napa County statement said he had been associated with the Yountville facility’s Pathway Home treatment program.
Mr. Wong had been a member of the Pathway Home until recently, when he was asked to leave, State Senator Bill Dodd said in an interview with The Times on Friday afternoon.
“These are young men or women that have been on the front lines in Afghanistan and Iraq and come back with a traumatic brain disorder,” Mr. Dodd said of the veterans in the Pathway program.
The Yountville center is the largest veterans home in the country, according to state officials. The campus, in the heart of California’s wine country, houses about 1,000 military veterans, providing independent living, dementia care and skilled nursing care for its residents.