The Carson dispatch center started out like every day that preceded it on Sept. 6, 2011.
Three employees were manning the stations, fielding 911 calls, handling fire alarms.
"It was one 911 call and then another. They kept coming in," said Marjorie Knowles, communications supervisor at the Carson City Sheriff's Dispatch Center.
She sent out the series of long beeps, known as a tone, over the radio system. This time, she did it longer than normal. Her co-worker had just picked up a 911 call about a shooting at IHOP.
She dispatched law enforcement after the tone. She did not contemplate or wonder. She just did.
"You don't have time to think. You just act on your experience and training," she said. "When there's a hot call, I try to take a deep breath."
Knowles and her fellow dispatchers' work made it seem to many on the other side of the radio - the law enforcement officers - that this was a drill, because her voice was so calm, they told her later during a debriefing.
"I thought it was a compliment," she said.
When Knowles listens to the tapes again, she can discern what law enforcement could not in her voice.
"When I listen back, I can hear something's up," she said.
That change in her voice was because she knew it was real.
"Your insides are just screaming," and the body is pumped full of adrenaline, she said.
First responders had no idea the cool-headed, cool-voiced Knowles struggled so.
The dispatcher's calming tone in an emergency "will be emulated by everyone else" and in the face of the shooting, the dispatchers remained completely calm, Carson City Sheriff Ken Furlong said. "They did phenomenal."
Furlong was among those who weren't sure it was really happening.
"Even I questioned if it was an exercise someone had forgotten to tell me about," Furlong said. "The way it was delivered," one did not pick up the severity of the situation from the dispatchers' voices.
Through her 27 years of experience, Knowles has heard a lot. But this was the worst, she said.
The years of experience, her training and her brain's muscle memory aided her both in fielding the calls and understanding that the event was real.
"The amount of calls, the emotional level of the callers and sometimes the terror. We could tell this was a real incident . . . just by their voices."
Knowles paged her fellow dispatchers to help staff the communications stations and the command post vehicle on scene. The dispatchers fielded more than two dozen calls within the first two minutes of the shooting, which left four people and the gunman dead.
"The first half-hour was crazy, chaotic," she said.
By the end of the dispatchers' shift, co-workers relieved them and allowed them to go to the first of a series of debriefings.
The emergency responders were "full of compliments," she said. What they said "made me feel good."
It wasn't just her professionalism. The debriefings were a catharsis.
"Just being able to talk about it helped," she said.
She needed it after standing up from her station.
"It hits you after you get up," she said. "It hits you at once and it's surreal, you don't believe what happened."
Knowles and her co-workers went to the recent memorial service.
"We move on but it's still there," she said.