A Santa Clara Valley Transportation Authority employee shot and killed nine people at a VTA maintenance yard in San Jose on Wednesday morning and also died there, authorities said.

The Santa Clara County Sheriff's Office first received reports of the shooting at 6:34 a.m. and dispatched deputies to the rail yard, which is adjacent to the sheriff's office's headquarters.

The county medical examiner-coroner's office identified the nine people killed in the mass shooting as Adrian Balleza, 29; Jose Dejesus Hernandez III, 35; Taptejdeep Singh, 36; Michael Joseph Rudometkin, 40; Paul Delacruz Megia, 42; Alex Ward Fritch, 49; Timothy Michael Romo, 49; Abdolvahab Alaghmandan, 63; and Lars Kepler Lane, 63. The coroner's office notified all next of kin before their names were released to the public.

Fritch had been in critical condition and was transported Wednesday morning to Santa Clara Valley Medical Center, where he died from his injuries later that day, according to the coroner's office.

Investigators, law enforcement officials and political leaders held a briefing Wednesday afternoon to shed more light on the shooting by a VTA employee, who was identified by the county as Samuel James Cassidy, 57.

A spokesperson for the sheriff's office said that explosive-detecting dogs and robots and members of the agency's bomb squad are expected to remain at the VTA's Guadalupe rail yard on West Younger Avenue into Thursday to ensure it is safe.

"We're going to be there throughout the night to clear every room and every crevice of that building," Deputy Russell Davis said.

Investigators with the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are also supporting the sheriff's office in investigating the shooting and supplying investigators with assets like ballistics and forensic equipment from the FBI's offices in Quantico, Virginia.

The employee opened fire during a shift change at the rail yard, with graveyard shift employees leaving the facility and day shift employees arriving, according to Davis.

More than 40 employees were at the facility at the time, San Jose Police Chief Anthony Mata said. In addition to the FBI and ATF, local law enforcement in Santa Clara County, the California Highway Patrol, the state's Office of Emergency Services and the Department of Homeland Security assisted during the initial active shooter response.

Davis and Santa Clara County Sheriff Laurie Smith argued that the death toll could have been even higher if law enforcement officers hadn't responded as quickly as they did.

"The deputy sheriffs from the sheriff's office, the officers from San Jose Police Department ran into the building while shots were being fired and I know that it saved many lives," Smith said at the briefing.

Davis noted that sheriff's deputies did not exchange gunfire with Cassidy and investigators are working under the assumption that he died by suicide. The spokesperson did not confirm whether a house fire at what is believed to have been Cassidy's home was connected to the shooting.

On Thursday, the sheriff's described Cassidy as a "highly disgruntled VTA employee for many years" but said a specific motive for the case, the Bay Area's deadliest mass shooting ever, remains under investigation.

Investigators located three semi-automatic 9mm handguns at the scene along with 32 high-capacity handgun magazines loaded with additional ammunition, sheriff's officials said.

Sheriff's crime scene investigators are utilizing high-tech equipment to survey the crime scene and allow the ability to recreate the events of the shooting for training purposes, according to the sheriff's office.

The VTA suspended all light-rail service in the system starting noon Wednesday, with bus shuttles providing limited service for riders, until further notice.

'A horrific day': Elected leaders, transit agencies react

Several local elected leaders who spoke at a briefing late Wednesday morning mourned the people who were killed in the shooting.

San Jose Mayor Sam Liccardo said it is "a horrific day for our city, and it's a tragic day for the VTA family ... our hearts pain for the families and the coworkers because we know that so many are feeling deeply this loss."

VTA board of directors chair and Sunnyvale Vice Mayor Glenn Hendricks described the Guadalupe facility as a maintenance yard where light-rail vehicles are dispatched from.

"VTA is a family, people in the organization know everyone," Hendricks said. "This is a terrible tragedy."

The VTA is also getting grief counselors in place for its employees, Hendricks said.

State and federal elected leaders offered his condolences to the victims and their families following the killings.

"My prayers are with the families and my gratitude goes to all the first responders," Rep. Anna Eshoo, D-Palo Alto, said in a tweet.

"Our mass shooting epidemic continues to give rise to unimaginable heartbreak and loss," state Sen. Dave Cortese, D-San Jose, said.

Some also called for more effective gun control measures.

Rep. Ro Khanna, D-Santa Clara, said he will continue to push for "common sense gun control measures."

"While much still remains to be confirmed at this time, one thing is abundantly clear: the gun violence epidemic will continue to rage unless we take concrete action to protect our country. It was our community today, but it will be someone else's tomorrow," Khanna said in an emailed statement.

Khanna said more than 80% of Americans favor measures like waiting periods, "red flag" laws and background checks.

"When I head back to Washington, I will continue to push for this urgently needed legislation," Khanna said.

State Sen. Bob Wieckowski, D-Fremont, said California lawmakers remain committed to "passing sensible gun laws so fewer victims will feel the pain and heartbreak that San Jose is feeling today."

At the Wednesday afternoon briefing, local officials expressed grief and outrage about the shooting, which came less than two years after Gilroy resident Santino William Legan, 19, shot and killed three people and injured 15 others at the Gilroy Garlic Festival in July 2019.

"To the victims, to those who've lost their lives and the families lost their loved ones, our hearts go out, but we are resolved to not make this meaningless, but to bring meaning at this tragic moment in our state and our nation's history," Gov. Gavin Newsom said.

County Supervisor Cindy Chavez noted that VTA continued service amid the shooting and only stopped when the transit agency issued an indefinite pause of light rail service at noon.

"These heroes — we all learned how to call essential workers 'heroes' — we're now calling on them to be heroes again," she said.

"We know that our entire community will need this moment and many others to mourn together," Liccardo said. "So we want to bring people together to be able to at least share a common humanity, particularly given all that we've been through over the last year-and-a-half, this is a time when we need to be together."

Caltrain and SamTrans officials shared their condolences in a joint statement.

"This is a dark day for the VTA and the City of San Jose," Caltrain board chair Dev Davis said. "We don't yet have all the details regarding this horrible act, but we stand with our member agency as they continue to serve the public amidst this tragedy."

"We are deeply saddened by the terrible shooting this morning," said SamTrans board chair Charles Stone. "Our hearts go out to everyone at VTA; especially the women and men who work to keep it running."

The killings also prompted the Giffords Law Center to Prevent Gun Violence to demand that national leaders address the country's gun violence crisis.

"This is an urgent crisis that requires immediate action. It is time for our national leaders to find the courage to act so that gun violence no longer leads to devastation on such a horrifying scale," said the center's executive director Robyn Thomas.

Remembering, honoring the victims

The city of San Jose will hold a vigil for the victims of the shooting Thursday at 6 p.m. at San Jose City Hall, located at 200 E. Santa Clara St.

Caltrain will provide free train rides Thursday evening to and from San Jose City Hall on trains 260 and 264, which arrive at the San Jose Diridon Station at 5:09 p.m. and 5:39 p.m. respectively. Passengers attending the vigil must let the conductor know they will exit at the Diridon station for the vigil.

After arriving at the Diridon station, passengers can then take VTA bus Rapid 500, Rapid 522, 64A, 68 or 22 to City Hall. People can also walk from the station to City Hall, about 1.2 miles.

People leaving the vigil can also ride free on Caltrain once they notify conductors that they attended.

Caltrain's schedules are available at caltrain.com. VTA's schedules are available at vta.org.

The San Jose-based community organization Working Partnerships USA and the South Bay Labor Council set up a fund to support families of the shooting victims. Donations can be made at act.wpusa.org.

A family reunification center has also been set up at the County Government Center at 70 W. Hedding St. VTA employees and their families can call 408-321-7550 for more information.

Any person who is feeling depressed, troubled or suicidal can call 800-784-2433 to speak with a crisis counselor. People in Santa Clara County can call 855-278-4204. Spanish speakers can call 888-628-9454.

People can reach trained counselors at Crisis Text Line by texting 741741.

Additional resources can be found here.

This story will be updated as more information becomes available.