FREMONT -- If residents see helicopters descending near Auto Mall Parkway on Sunday, they shouldn't worry that the city is under attack.
The noise and flurry of activity are part of a simulation of the aftermath of a natural disaster, created so that fire and police agencies and military personnel can prepare to work together if a disaster hits the Bay Area.
The six-hour drill, called Operation Rolling Chaos, will be held at Unitek Education, a Fremont company that provides professional training for emergency medical technicians, as well as public safety and IT employees, said Eli Soto, a Unitek official who helped plan the event.
"It's an opportunity for these agencies to receive real hands-on experience in working together on how to respond to a natural disaster or other tragedies," Soto said.
Organizers of the event, to run from 8 a.m. to 2 p.m., aim to simulate the breaking of Anderson Dam, near Morgan Hill. A 2009 study by the Santa Clara Valley Water District predicted a dam break there could unleash a 35-foot-high wall of water that would engulf surrounding areas, Unitek officials said.
To re-create fire and police agencies' initial reaction to such a disaster, Unitek's simulation will deploy 12 vehicles, two buses, eight ambulances and three helicopters, Soto said. Nearly 500 people from the military, including Army Reserve and state military reserve units, and several local agencies -- such as Fremont firefighters
During past natural disasters, such as Hurricane Katrina in 2005, a disconnect between first responders and the military sometimes has hindered rescue efforts, Soto said. The simulation's goal is to help organizations get on the same page so they can standardize their operating procedures long before a disaster strikes, he said.
"No one wants a disaster to happen, but the fact is, they do," said Eric O'Neal, a Unitek employee and the drills's lead instructor. "People may say there is no way to be 100 percent prepared, but it won't stop us from trying."
Contact Chris De Benedetti at 510-353-7011. Follow him at Twitter.com/cdebenedetti.