Los Angeles ? Police are investigating the accident that killed celebrity plastic surgeon Dr. Frank Ryan, including whether texting or tweeting may have played a role.

“We haven’t confirmed anything regarding the cause of the collision,” California Highway Patrol officer Steve Reid said Wednesday, adding that detectives are “looking into several factors, including texting and Twittering that may have played a role in the accident.”

Ryan’s last post on Twitter was at 3:10 p.m. Monday. It included a photo of his dog looking out at the ocean with the caption, “Border collie jill surveying the view from atop the sand dune.”

Ryan, 50, had posted earlier that he hiked to the top of a sand dune near Pacific Coast Highway in Malibu.

Police say the doctor’s 1995 Jeep Wrangler went off the side of Pacific Coast Highway near Malibu and landed on its roof Monday afternoon. The crash was first reported at 4:34 p.m. by a motorist who witnessed the accident, Reid said.

A spokesman for Twitter says the time stamps on tweets reflect the time zone in which the account was created.

The dog was seriously injured in the crash and taken to an animal hospital, police said.