SAN BERNARDINO, Calif. — During a tension-filled day as a nearby mass shooting made the national news, school bus drivers here stepped up to assist in efforts to safely transport survivors after two shooters killed 14 people.

William Weisberg, area general manager of the San Bernardino customer service center for Durham School Services, was just about to join a conference call on Dec. 2, at approximately 11 a.m. Then, one of his employees ran into his office and told him there was an active shooter incident unfolding nearby.

Weisberg’s first reaction was to lock up the building, which is located only half a mile from where the shooting took place, at the Inland Regional Center, and do everything he could to protect as many employees as possible, he said.

“My first thought was, we’ve got to close our garage bay doors, lock all the doors, get everybody inside, tell all the drivers that were on route not to come back to the yard, because the doors were closed, they couldn’t get in,” he explained. “I have never been in this position before. I didn’t know how to react. The safety of my employees was always at the top of my mind.”

Employees all moved quickly to take these steps in an increasingly tense atmosphere in which they had no idea what was happening from moment to moment.

“Everyone’s on edge because the shooters were still on the loose,” Weisberg said. “We didn’t know if they were on foot, or in a car. We had no information, and the whole time, I’m thinking, ‘If they’re on foot, they could be in my back lot, hop a fence and be on our property.’ So, I kept an eye [out] to make sure that wasn’t happening.”

Just about half an hour later, Weisberg received a call from the director of transportation for San Bernardino City Unified School District, who asked for bus drivers to go to the site of the shooting to shuttle survivors away from the scene. The dispatcher asked if any drivers would like to volunteer, and four offered to help. From about 11:45 a.m. to 8 p.m. nonstop, school bus drivers and bus drivers for Omnitrans, the local public transit system, shuttled hundreds of survivors from the scene of the shooting to designated safe areas — the Rock Church & World Outreach Center in San Bernardino and the Rudy C. Hernandez Community Center — where they were able to reunite with family members and police officers took statements.

“[The drivers] have some incredible stories,” Weisberg said. “Every time they talk about it, they get a tear in their eye, because they were right there in the heat of it.”

The drivers felt safe while transporting survivors because there were three California Highway Patrol officers on board each bus, and police officers were on the roads, which were closed, to escort the school buses.

The drivers will be formally recognized by Durham School Services at an employee meeting in January, Weisberg said, and added how proud he is of his employees.

“Being in the middle of that for the eight hours they spent helping the community, that was really a rewarding and scary experience at the same time for all of them,” Weisberg said.

While Durham has an active shooter plan, the shooting has prompted Weisberg to consider practice drills.