On Oct. 5, 2011, Shareef Allman stormed into an employee meeting at the Lehigh cement quarry in Cupertino.
Alllman pulled out a gun and opened fire, killing three of his co-workers and wounding several others. Allman had told friends his co-workers were trying to get him fired. So he confronted them in the dawn hours that day.
A year and a half later, some of the victims' family members are still grieving and angry.
“It has been very, very difficult all the time. It's like being in an empty hole,” said Viola Munoz, whose husband Mark was one of the victims.
“It's been really hard. I go day by day, and there’s days when I won’t get out of bed. He was my rock," said Melina Pinon, the widow of Manuel Pinon.
On Wednesday, Munoz and Pinon, surrounded by their children, told NBC Bay Area that they are suing Lehigh, claiming wrongful death.
The families say their husbands warned the Lehigh human resources department and their supervisors about Allman, claiming he was unstable. They said they reported that Allman made death threats, and that he carried a gun in his car.
The suit also claims the company did nothing about the concerns.
“I do feel it was preventable if management had taken the correct action that should have been taken. We miss him every day," said Pinon’s daughter Salina.
Lehigh released a statement to NBC Bay Area, saying, "The company intends to vigorously defend itself against the allegations in these complaints. As a matter of policy, we cannot provide further comment on active litigation."
A memorial now sits at the entrance of the quarry, with the bronze faces and names of John Vallejos, Manuel Pinon, and Mark Munoz.
“You just have that empty feeling that no one is going to be able to fill it,” said Salina Pinon.
“It’s been as painful as anything could possibly be,” said Mark Munoz’s son, whose name is also Mark.
“When my husband took that bullet, I felt it, I felt it,” said Viola Munoz. “He made my life absolutely beautiful, and that is gone. That's been ripped from my soul.”