Homeland and 24 Producer Sued Over Fatal Crash

Here's what we know ... Law enforcement sources tell TMZ ... Gordon's wife, Cambria, was driving in Santa Monica on July 20th when her cell phone fell off the seat onto the floor of the car. Cambria reached down to retrieve the phone when her car struck 83-year-old pedestrian William Howard Smerling.

Smerling was taken to the hospital, where he hung on but died a month later. According to the lawsuit, Smerling had the right of way and Cambria was negligent by taking her eyes off the road. Howard is being sued because he's the registered owner of the car along with his wife. Under California law, the registered owners are responsible for the misdeeds of those who drive with their permission.

And law enforcement sources tell us ... Cambria will be charged with misdemeanor vehicular manslaughter. The maximum penalty is 1 year in jail, but typically first offenders end up on probation.