The private security officer assigned to Mission Elementary School when vandals broke into the school last month smashing windows, televisions and computers didn't respond when the alarm went off.
David Travers, president of Guardian Security, said that the company is assuming responsibility for the school's losses.
"This was an unfortunate situation where a person negated to do what they were supposed to do," Travers said.
He wouldn't say whether the security officer still works for the company. But he said there had been some personnel shifts and the officer no longer patrols Mission Elementary.
"This is the first time that we have ever had anything happen," he said. "We have taken steps internally to make sure that it never happens again."
Antioch police continue to investigate the havoc wreaked on Mission Elementary early in the morning on Nov. 17. Antioch Unified School District officials are still calculating the cost of damages, but preliminary estimates put it around $20,000.
The Antioch school district contracts with Guardian to respond to alarms. Guardian officers then call the police if there is a problem.
The two-step procedure saves precious police time on false alarms, which are common. Travers said that something as small as a gust of air rustling a piece of paper posted on a wall can trigger an alarm. He said the security officer probably assumed that the Mission alarm was false. Guardian has successfully stopped school vandals many times, he said.
"There have been numerous occasions where we have run people off, where we have caught kids breaking into the schools. Sometimes we have helped police catch them by following them," Travers said.
Although little was stolen from Mission besides a digital camera, the vandals did a great deal of damage. Shattered glass covered three classrooms. They broke a marble jar, pounded small hammer-size dents into the walls, ripped out a phone outlet and shattered windows, computer monitors and televisions screens.