WASHINGTON, D.C. --- The National Highway Traffic Safety Administration has released some new details about the fatal car crash that triggered Toyota's recall of 3.8 million Toyota and Lexus vehicles. 

The accident, which killed off-duty California Highway Patrol Officer Mark Saylor and three members of his family, took place on Highway 125 in suburban San Diego when the Lexus they were traveling in reportedly accelerated out of control. Saylor was driving a 2009 Lexus ES 350, a loaner from a car dealership servicing his own car. 

The new report indicates that the Lexus' accelerator pedal design may have been a contributing factor in floor mat entrapment. "Beyond the main pivot, the lever is not hinged and has no means for relieving forces caused by interferences," investigators said. 

According to the Los Angeles Times, the report states that the lower edge of the accelerator pedal was "bonded" to the rubber floor mat. The vehicle had all-weather floor mats designed for a different vehicle model -- a Lexus RX40h SUV. A photo in the report shows damage to the section of the floor mat surrounding the gas pedal. 

According to the report, the mat was unsecured by the vehicle's retaining clips. One of the two clips had pulled out of the carpeting and was lying under the floor mat. The other clip was still attached to the carpeting but not hooked into the floor mat. Moreover, investigators noted that the vehicle's brake surfaces showed signs they had been worn down because of heavy braking against the full force of the Lexus engine. 

Until the automaker devises a long-term remedy, Toyota is asking all owners of the recalled vehicles to remove the driver's side floor mats. 

It's also important for drivers, in general, to be aware that in Toyota vehicles that use a push-button (keyless ignition) start system, turning the engine off in an emergency situation when the car is in motion isn't the same as it is when the vehicle is in park. When the car is in park, a quick push of the button turns off the engine. But if the car is actually moving, the driver must hold down the button a full three seconds to shut off the engine. 

Meanwhile, the San Diego County Sheriff's Department is leading another investigation of the Saylor crash. That investigation is ongoing.