When a masked, black-clad gunman stormed into a training session and holiday party for San Bernardino county health workers in December, only a handful knew instantly to run for the exits.
In a terrible twist of fate, some of the workers had previously been trained on how to deal with an active shooter in that very same conference room, according to a U.S. Department of Justice report released Friday about last year's terrorist attack in San Bernardino.
They thought this must be more training and just stood there, until the carnage became starkly real.
A second assailant entered the room and joined the first, shooting anyone they could. In two to three minutes, they shot over 100 rounds, killing 14 people and wounding 22, in what was at the time the third deadliest attack in the U.S. since 9/11.
The report, "Bringing Calm to Chaos," reviewed the police response to the shooting, seeking lessons for future attacks, and provided new details about what occurred in the conference room. It described victims pleading for their lives and first responders having to step over bodies to reach the wounded.
The killers, Syed Rizwan Farook, 28, and his wife, Tashfeen Malik, 29, had been inspired by Islamic terrorists but had no direct ties to them.
Farook, raised in Riverside, was a health inspector in the department, known as a tech-savvy and diligent worker who helped his colleagues with computer problems. According to the report, some of them thought he became "more stoic" after he traveled to Saudi Arabia and returned with Malik, a native of Pakistan, as his new bride, the report said.
Still, just months before the shooting, they threw him a baby shower at the office.
On the morning of Dec. 2, about 80 staff members from the Environmental Health Department arrived at the Inland Regional Center on the south side of town for the training and holiday party. A large Christmas tree with ornaments stood in the corner.
"They watched a training video and then moved on to a team-building exercise as a way for staff members to get to know one another better," the report's authors wrote.
"Around 10:30 a.m., one of the employees, Rizwan Farook, an environmental health inspector, got up from his chair and left the meeting. Colleagues noticed him looking at his phone before he departed, but no one thought much of it. He had left his bag on the table, and they expected he would be back to retrieve it."
A technical problem caused an unscheduled break at 11, with staff going to the bathroom, checking phones, grabbing food.
Suddenly, they heard sharp pops outside, and the door swung open. Farook and Malik wore masks. They walked between the tables gunning down Farook's co-workers, some who considered him a friend.
"If someone moved or made a sound, the shooters fired one or multiple shots into their body," according to the report.
In the chaos, one round pierced a fire sprinkler pipe, causing water to gush from the ceiling. The gun smoke made it difficult to see. Many got out the doors, and escaped outside or barricaded themselves in other rooms in the building. One woman was hit by a bullet that penetrated a wall. Some of the fleeing survivors crossed the bodies of the two people he killed before entering the conference room.
Two or three minutes after they entered, Farook and Malik fled the scene in a black SUV. (They would be killed nearby in a shootout with police that afternoon.)
Four San Bernardino police officers arrived within minutes of the attack, followed by detectives from Fontana. A lieutenant had just eaten lunch and was headed to get gas, a detective had stopped at headquarters to use the bathroom, and motor officer had just picked up a sandwich.
"If you were picking a team, the four of us were not the ones that would be picked first, but we have all had active shooting training," said Mike Madden, the San Bernardino police lieutenant who led the initial charge into the building, told the Justice Department. "It just seemed like we knew what our roles were and what we were supposed to do."
Madden said the first radio calls for "shots heard in the area" did not cause any particular alarm — it's a frequent call in San Bernardino, one of the highest-crime cities in California.
But a third caller "had made it clear not only that this was real but also that there were multiple shooters and they were still there."
More than three miles away, the homicide detective was filling in on patrol when he heard the call. He flipped on his lights and siren and raced to the Inland Regional Center, then "cursed at himself for leaving without his 'go bag' filled with a helmet" and tactical gear, and forgetting his patrol rifle.
The four officers gathered outside the three-story compound.
The lieutenant told them to stay in a diamond formation and to look for explosive devices.
As they approached the building, one of them said: 'Okay, it's time to go.' "
The first officers to arrive in the conference room were horrified by what they saw.
"It looked like a bomb had gone off. Bodies were strewn across the floor. Many had devastating wounds. Blood was everywhere, the report said. "The smell of gunpowder filled their nostrils, and the sprinklers sounded like they were hissing. Wounded victims pleaded with them to stop, taking hold of the officers' legs in hopes of receiving aid."
"It was the worst thing imaginable — some people were quiet, hiding, others were screaming or dying, grabbing at your legs because they wanted us to get them out, but our job at the moment was to keep going," one patrol officer said in the report. "That was the hardest part, stepping over them."