The incident, which began at about 10:30 a.m. local time on Friday at the sprawling facility in the heart of Napa Valley's wine country, some 60 miles (100 km) north of San Francisco, ended nearly eight hours later.
A gunman and three hostages are dead after a standoff at the Veterans Home of California in Yountville.
Relatives hug each other after the shooting at an elderly home in Yountville, California.
Wong exchanged fire with a sheriff's deputy at around 10.30am but then went silent, despite repeated police attempts to contact him.
The Napa Valley Performing Arts Center at Lincoln Theater in Yountville, CA reports that the 80 students and faculty from Justin-Siena High School in Napa, rehearsing for a production of "Guys and Dolls" at our theater, remained safe at all times on Friday during the unfortunate incident at the Veterans Home of California. A knowledgeable source said all four had been shot.
Christine Loeber was executive director of the Pathway Home, a treatment program for veterans from the wars in Afghanistan and Iraq.
Yountville Mayor John Dunbar said Saturday the shooting a day earlier at the Pathway Home was a "terrible tragedy". It was not immediately known whether she worked with state or federal VA.
Wong had been an Army infantryman who served a year in Afghanistan from 2011 to 2012.
Department of Defense officials said Wong was a decorated US soldier who served on active duty from May 2010 to August 2013. Kamer's wife, Devereaux Smith, was one of the people not allowed to leave.
Indonesian zoo slammed after orangutan caught smoking cigarette
In May 2016, Yani, a Sumatran elephant, was photographed there, reportedly "crying hours before it died". The viral video was shot Sunday at Bandung Zoo, about 90 miles southeast of the capital, Jakarta .
The San Francisco Chronicle, said Wong, who lived in Sacramento, had been asked to leave the programme two weeks ago.
According to radio transmissions between officers at the scene and dispatchers, Wong burst into the home wearing "a stash of bullets around his neck" and his waist.
Wong's rental vehicle was found nearby. It was a setting of the 2017 fictional movie "Thank You for Your Service", about a Marine platoon leader with PTSD. All of us at The Pathway Home are devastated by today's events. The center has treated some 450 people.
The Veterans Home posted on their Facebook page that emergency response protocols were activated and they were working with law enforcement. Golick and Gonzalez were counselors and Loeber was the director of the program. "Nobody helps them understand that when they get back they have to reprogram their nervous system to operate at a different caliber so they can be successful civilians".
However, Golick's father-in-law said she had recently ordered Wong removed from the program. She described herself as a licensed marriage family therapist with more than 16 years of clinical practice.
"These courageous women were accomplished professionals who dedicated their careers to serving our nation's veterans, working closely with those in the greatest need of attention after deployments in Iraq and Afghanistan", The Pathway Home said in a statement.
President Trump offered his condolences early Saturday.
The mayor of a California town where a former soldier killed three women at a veterans treatment centre says the employees will be remembered as handsome people and called the gunman "one of our heroes who clearly had demons". They spoke of the three victims who worked for the program and the gunman.