▶ Watch Video: Gunman’s dark past uncovered as San Jose mourns victims

One of the nine victims killed in the San Jose rail yard shooting helped save the lives of his colleagues by hiding them in offices and calling others who had yet to arrive at work to warn them of the danger, according to statements from his family and one of his coworkers.

In a statement Thursday, the family of Taptejdeep Singh said they will remember the 36-year-old light rail operator as a hero. The family said eyewitnesses and others told them Taptejdeep “spent his final moments trying to keep others safe.”

“From what we have heard, he reacted quickly to get colleagues into secure offices and was frantically calling others who would have been coming in for a shift change to warn them about the shooter. We understand that he was attempting to secure his building when he was killed,” the statement said.

“Even in these moments of chaos, Taptejdeep was living by the values of Sikhi: living in service and protection of others. We believe that if the shooter had ever asked our brother for help, Taptejdeep would have gone above and beyond for him like he did for everyone he crossed paths with; he never harmed anyone, and no one who knew him would ever want to harm him,” the statement continued.

Sukhvir Singh, a colleague with no relation to Taptejdeep, said he received one of the warning calls.

“Taptejdeep called me to warn me that there was an active shooter in Building B and to go hide or get out immediately. He told me he was with Paul, another victim, at the time. From what I’ve heard, he spent the last moments of his life making sure that others — in the building and elsewhere — would be able to stay safe. Because of him, so many people were able to go home to their families,” Sukhvir said in a statement.

Taptejdeep Singh had worked at the California transit facility for eight years, according to the Sikh Coalition. He was born in Punjab, India, and moved to California with his parents nearly two decades ago. He is survived by his wife, a 3-year-old son and a 1-year-old daughter.

Sheriff Laurie Smith said the suspected gunman, 57-year old Samuel Cassidy, appears to have targeted the victims: “We do know that he confronted one person and said, ‘You know, I like you, get out of here,’ and then went to the next. The person that he did not shoot was not an employee there.”

Police said Cassidy acted alone and died of a self-inflicted gunshot wound. His ex-wife, Cecilia Nelms, says he struggled with his anger during their 10-year marriage. “That was one of our biggest problems. He was very quiet, keep things to himself,” she told CBS News.