Star Trek actor Anton Yelchin was killed when he was struck by his own car, police have said.
The American actor, 27, was hit by the vehicle as it rolled backwards down his drive in Studio City, California, according to Los Angeles police officer Jenny Hosier.
The car pinned Yelchin against a brick letterbox pillar and a security fence.
He had got out of the car, but police did not say why he was behind it when it started rolling.
Yelchin was on his way to meet friends for a rehearsal, Ms Hosier said. When he did not arrive, the group went to his house and found him dead.
Yelchin started his acting career with parts in indie films and television shows such as Judging Amy and The Practice before getting his big break in 2006 crime thriller Alpha Dog.
He is best known for playing Pavel Chekov in the rebooted Star Trek films.
The actor is in the third film in the franchise, Star Trek Beyond, which is due to be released in the UK next month.
Several celebrities have paid tribute to Yelchin on Twitter following the accident on Sunday morning.
His Star Trek co-star Zachary Quinto wrote: "Our dear friend. our comrade. our anton. one of the most open and intellectually curious people i have ever had the pleasure to know. so enormously talented and generous of heart. wise beyond his years. and gone before his time. all love and strength to his family at this impossible time of grief."
Actor John Cho, who also appears in the films, said: "I loved Anton Yelchin so much. He was a true artist - curious, beautiful, courageous. He was a great pal and a great son. I'm in ruins."
Justin Lin, director of Star Trek Beyond, said: "Still in shock. Rest in peace, Anton. Your passion and enthusiasm will live on with everyone that had the pleasure of knowing you."
Actress Anna Kendrick wrote: "This is unreal. Anton Yelchin is such a talent. Such a huge loss."
Night Manager actor Tom Hiddleston tweeted: "Absolutely devastated to hear about Anton Yelchin. He was such a gifted, natural actor & a deeply kind man. My thoughts are with his family."
Little Britain star Matt Lucas said Yelchin was "an amazing actor".
Glee actor Kevin McHale said: "Anton Yelchin has always been one of my favorite actors. I've seen every movie. This is awful. Im so sorry for his family & friends."
Yelchin, an only child, was born in Russia. His parents were professional figure skaters who moved the family to the United States when Yelchin was a baby.
The actor's publicist, Jennifer Allen, confirmed his death and said his family requests privacy.