Bob Clark, writer and director of the cult 1980s film Porky's, has been killed in a car accident.
The 67-year-old film-maker died along with his son Ariel, 22, in the accident near Los Angeles, on Wednesday.
The 24-year-old driver of the other vehicle, and a female passenger, were treated in hospital for minor injuries.
A police spokesman said the driver was being investigated on suspicion of driving without a licence and being under the influence of alcohol.
Clark specialised in horror films and thrillers in the 1970s, with films such as Children Shouldn't Play With Dead Things, Murder by Decree, Breaking Point and Black Christmas.
His breakout success came with 1982's coming-of-age comedy Porky's. He followed it two years later with Porky's II: The Next Day.
In 1983, A Christmas Story, starring Darrin McGavin, Melinda Dillon and Peter Billingsley, was a modest success at the box office, but critics loved it.
The film, about a nine-year-old boy who wants a model air rifle for Christmas, has become a perennial holiday favourite in the US.
Scott Schwartz, who played Flick in A Christmas Story, said he was devastated at Clark's death.
He said Clark was "one of the nicest, sweetest guys that you'd ever want to come in contact with".
Among Clark's other films were Sylvester Stallone and Dolly Parton's Rhinestone, Gene Hackman and Dan Aykroyd's Loose Cannons, and Baby Geniuses.