A California highway patrol officer and three family members were killed when their car's accelerator stuck and they crashed going 100 mph. A traffic expert tells us what to do if we ever find ourselves in a similar situation.

Cops say someone in the 2009 Lexus ES 350 called 911 just after 6:30 PM last Friday to report the stuck accelerator. Witnesses said the car was traveling northbound on Route 125 in Santee, CA, when it slammed into the rear end of a Ford Explorer, plowed over a curb, and went through a fence before hitting an embankment and going airborne. It reportedly rolled several times before stopping and bursting into flames in the nearby San Diego River basin, according to the San Diego Union-Tribune.

Chris Lastrella 911 Call Before Crashing sound bite

Mark Saylor, 45; his wife, Cleofe, 45; his daughter, Mahala, 13; and his brother-in-law, Chris Lastrella, 38, were all killed in the crash, according to the CHP.

The car he was driving was a loaner car from a local car dealership, as Saylor had recently dropped off his regular vehicle for servicing.

Toyota, which makes Lexus cars, had recalled the "all-weather" floor mats in its 2008 version of that car model because of complaints about them sliding forward and jamming the accelerator. A sales manager at the dealership said he wasn't sure which mats were in the Lexus loaned to Saylor.

Toyota issued a statement saying the company is deeply sorry to hear about the Saylor incident.

"We are unable to comment on this tragic accident until all the facts are known," the statement said. "It is important to avoid speculation and allow any investigation to run its course."

What should we do if this ever happens to us? We called our friend Mr. Traffic, a.k.a. Kenny Morse, for guidance.

"Knowing what to do in the unlikely case of a gas pedal sticking might save your life," he says. "First of all, this happens rarely, but if you keep your wits about you and do not panic, it can make all the difference."

Here are his top tips:

• First, try to hit the pedal to make sure nothing is forcing it down.

• Next, PUT THE CAR IN NEUTRAL IMMEDIATELY, and gently start to brake, being aware of the traffic around you, and pull the car to the side of the street or road as soon as possible.

• The last resort is turning off the ignition, but you have to make sure that you do not lock the steering wheel. You will lose your power in the brakes and steering. DO NOT try to drive the vehicle, as it will rev the engine to a dangerous level.

"Knowing what to do in a potential emergency is what makes a driver a driver," Morse says. "Anyone can step on the gas and go straight, but do you know how to avoid a collision, or something like this?"

For more on how to deal with emergency situations, check out www.mrtraffic.com.