A 36-year-old Sikh man was among eight people killed in the latest mass shooting incident in the US, authorities in San Jose, California, said on Thursday.

Taptejdeep Singh, who was a light rail operator at the Valley Transportation Authority (VTA) for nine years, was the first victim to be publicly identified by his family, The Mercury News reported.

Singh, born in India and raised in Union City, California, leaves his wife, three-year-old son, one-year-old daughter, and a grieving Sikh community in the San Francisco Bay Area, which described him as a “helpful and caring” man.

Co-workers at the light rail yard of the VTA hailed Singh as a hero, saying he left the safety of an office room, where some colleagues were hiding, to help others escape the line of fire.

Samuel Cassidy, 57, a VTA maintenance worker on Wednesday gunned down eight of his co-workers and critically injured another in a one of the deadliest shootings in California this year.

As police arrived at the scene, the killer died of a self-inflicted gunshot wound.

The gunman who opened fire bypassed certain people and appeared to select those he shot, a witness said.

“He ... was targeting certain people. He walked by other people,” Kirk Bertolet, a worker at the Santa Clara Valley VTA in San Jose, told CNN affiliate KGO on Wednesday night. “He let other people live as he gunned down other people,” Bertolet said.

The gunman, armed with two semi-automatic handguns, shot co-workers in two buildings around the time of a morning shift change before taking his own life in front of responding law enforcement officers, authorities said.

At least eight of the nine killed were VTA employees, and investigators are trying to determine the motive, officials said.

Singh worked at a separate building from where most of the other victims were found, giving the impression that Cassidy had selected his victims.

Singh was fatally shot in the stairwell of a VTA building, the report said.

Singh’s brother-in-law, P.J. Bath, another light rail operator at the VTA, confirmed that the shooter and Singh were in different buildings initially but said nothing of the victims being decided earlier by the killer.

“He just happened to be in the way, I guess. He was always helpful to everyone and caring,” Bath said. “We are in very deep grief,” Singh’s uncle Sakhwant Dhillon told the San Jose-based newspaper.

“He told people, ‘be careful, hide’. He was running around the building to save others’ lives. He was a good person. He helped everybody,” Dhillon said.

Singh’s brother Bagga Singh said he was told that his brother had saved a lady when he “rushed down the stairway”, where he was eventually shot.

Singh may be considered a hero, but “he should have saved his life, too. We lost a good person”, Bagga said.

Emotional scenes were seen at the Red Cross Centre in the city where families of the victims gathered after the incident was reported.

Singh’s family, including his father, hugged and cried.

The other victims of the shooting were identified as Paul Delacruz Megia, 42, Adrian Balleza, 29, Jose Dejesus Hernandez, 35, Timothy Michael Romo, 49, Michael Joseph Rudometkin, 40, Abdolvahab Alaghmandan, 63, and Lars Kepler Lane, 63. The eighth person who was killed was identified as Alex Ward Fritch, 49.

Minutes after the incident, a fire was reported at Cassidy’s home, about 13km from the VTA office.

The fire was extinguished in an hour-long operation. Police said a separate investigation has been launched into the fire.

Cassidy, the identified gunman, resented his work, his ex-wife Cecilia Nelms told CNN affiliate the Bay Area News Group.

He often spoke angrily about his coworkers and bosses and at times directed his anger at her, Nelms said.

When the two were married, he “resented what he saw as unfair work assignments” and “would rant about his job when he got home”, she said.

Meanwhile, President Joe Biden reacted to the latest shooting incident by urging Congress to “take immediate action” on gun legislation. “Enough,” he said on Wednesday.

“Once again, I urge Congress to take immediate action and heed the call of the American people, including the vast majority of gun owners, to help end this epidemic of gun violence in America.”

The shooting is the latest example of America’s gun violence scourge.

It is the 232nd mass shooting this year in the US, according to a tally by the Gun Violence Archive.