The adult stepchildren of a woman killed in February in a four-car crash that also included Bruce Jenner have filed a civil lawsuit against the former Olympian and reality TV star.

Jenner, who publicly spoke to ABC’s Diane Sawyer on April 24 for the first time about being transgender, said at the time of the accident that he was cooperating with police as they investigated the fatal crash. It occurred on a tricky stretch of the highway, where the road is narrow and twisting.

Kimberly Howe was driving her Lexus on Pacific Coast Highway in Malibu, California, when Jenner struck the rear of her car, “propelling her vehicle into the opposite lanes of traffic,” according to the lawsuit filed by her stepchildren, Dana Redmond and William Howe. “Ms. Howe’s vehicle was then struck head-on by another vehicle, killing her.”

The lawsuit calls for unspecified damages and the cost of the suit.

Reached by CNN on Friday, May 1, Jenner publicist Alan Nierob said he had no comment regarding the lawsuit.

Jenner was not injured in the crash, Nierob said at the time. Shortly after the accident, Nierob provided a statement from Jenner to the family.

“My heartfelt and deepest sympathies go out to the family and loved ones, and to all of those who were involved or injured in this terrible accident,” Jenner said in a statement released a day after the February 7 accident. “It is a devastating tragedy, and I cannot pretend to imagine what this family is going through at this time. I am praying for them. I will continue to cooperate in every way possible.”

Jenner first catapulted to fame after winning the 1976 Olympic decathlon and now draws the celebrity spotlight for his role in the “Keeping Up With the Kardashians” reality show and his decision to talk publicly about his gender identity.

Authorities hadn’t determined who was at fault in the crash, Sgt. Phillip Brooks of the Los Angeles County Sheriff’s Department told CNN in February.

That day, Jenner was driving a black Cadillac SUV that was the third vehicle involved in a multiple rear-end collision, Brooks said.

The first vehicle was a black Toyota Prius, deputies said. Behind it was Kim Howe’s white Lexus sedan, which also hit its brakes.

Jenner’s Escalade was towing a trailer with an all-terrain vehicle on it when it ran into the Lexus from behind, Brooks said. The Lexus spun into oncoming traffic and was hit by a Hummer H2.

The department later opened a vehicular manslaughter investigation, according to CNN affiliate KTLA. The investigation will focus on everyone in the case, not just one person, a source told CNN legal analyst Mark Geragos. When contacted Friday, however, sheriff’s representative Nicole Nishida wouldn’t confirm that authorities had opened a vehicular manslaughter case.

The Sheriff’s Department said on its Facebook page that the surviving drivers were cooperating with investigators.

A deputy said Jenner voluntarily took a field sobriety test, was questioned and went home. Jenner passed the test, according to a report from investigators.

Five children and two adults were hospitalized with injuries, authorities said.

Jenner won the 1976 Olympic decathlon with a world record score for the 10-discipline event. He quickly capitalized on his success with Wheaties commercials, appearances and other ventures. He also became an actor, appearing in the drama “CHiPs” in 1981 and occasionally playing himself on shows such as “Silver Spoons.”

More recently, he has gained fame as the well-known stepfather of Khloe, Kim and Kourtney Kardashian on their family’s E! entertainment network reality show. He and Kris Jenner, the show’s matriarch, divorced last year.

E! said Jenner was not shooting for “Keeping Up with the Kardashians” on the day of the accident.