When night falls in Oakland, the city's 911 dispatchers tend to get busy.

Inside an anonymous-looking building in an East Oakland office park, they hunker down at workstations and stare into arrays of computer monitors displaying information on recent and incoming calls and on the status of each incident. The atmosphere is subdued, with dispatchers speaking mostly in hushed tones.

The calm is deceiving.

"Oakland's a crazy beast," 911 dispatcher Nicole Friend says. "We're very busy in here, and you get very used to being busy in here."

Friend is a jovial woman with a dry wit. She said in addition to all the life-and-death calls she handles -- people reporting crimes in progress or victims who need immediate attention -- she also hears from members of the public who sound like they've watched a little too much "CSI."

She recalls the man who called in to report his car had been burglarized. He wanted the half-eaten burrito the thief had apparently left behind to be swabbed for DNA.

No -- not gonna happen, Friend says, not even if you could run the burrito for DNA.

"We have people getting shot -- like, legit calls,"  Friend says. "We can't swab the burrito."

Calls like that are part of a never-ending flow of phone traffic to the 911 Dispatch Center. When the year is up, Oakland will have logged more than a half-million 911 calls. That's an average of about 1,400 calls a day, covering everything from complaints about vandalism to fires and traffic accidents to shootings and domestic violence.

Due to understaffing, the 911 center has its hands full. On average it takes Oakland dispatchers in Oakland about 16 seconds to pick up a 911 call. That compares with a recommended standard from the National Emergency Numbers Association that 90 percent of incoming calls should be answered in 10 seconds or less.

"We need people," says dispatch supervisor Eugenia Oliver, an 18-year veteran.

Oakland has 74 staffers working in its 911 center, including 11 trainees.

Those new hires are welcome progress, according to Regina Harris, who heads the 911 center. But she notes those trainees must each be paired up with a staff dispatcher for a year. That means those veterans are sometimes mentoring instead of answering calls and dispatching first responders.

The impact of understaffing goes beyond taking longer to answer incoming calls. According to the Transparent California database, mandatory and voluntary dispatcher overtime cost the city more than $1 million in 2013. Some Oakland dispatchers work so many overtime hours they increase their base pay by 50 percent. Experts say all those extra hours increase the risk for errors on the job.

Oakland could face an even bigger tab for dispatcher overtime when the 911 center starts taking wireless calls.

At this stage Oakland is the only major city in the state that still routes all mobile phone calls through the California Highway Patrol.

The CHP redirects wireless calls meant for 911 centers in cities around Oakland. It also dispatches all wireless medical calls directly to the city's Fire Department. This significantly lessens the call volume for Oakland.

But there's a big downside. In an emergency, time is critical. And the process of having the CHP triage and reroute calls can lead to significant delays.

The delay is long enough that the Oakland Police Department urgers wireless callers to use a separate number, not 911, if a crime is in progress.

Harris says her center would get about 150,000 more calls a year if Oakland were to start taking wireless calls directly. The plan now, she says, is to phase them in over the next three years, because there's no way Oakland could handle them based on current staffing.

"So we're just moving cautiously," Harris said.

When Oakland does start taking 911 calls directly, Harris estimates the city will need to hire at least 20 more dispatchers.

Harris won't be there to see that. She says she plans to retire in the spring after 31 years in the 911 profession. So her job will be open as well.