Los Angeles, California (CNN) -- The Beverly Hills plastic surgeon who remade Heidi Montag died when his Jeep plunged off a Malibu highway into the ocean Monday, a California Highway Patrol spokesman said.

Dr. Frank Ryan, 50, had just finished hiking with his border collie on a giant sand dune along the Pacific Coast Highway when the crash happened, according to his own Twitter message posted minutes earlier.

"The Jeep veered to the right and ran off the roadway," Officer Steven Reid said. "The Jeep overturned down a rocky embankment towards the ocean and eventually came to rest on its roof."

The dog was seriously injured, Reid said. It was taken to a veterinary hospital for treatment.

"He was the most amazing person I have ever known," reality TV star Montag said in tweets posted Tuesday morning. "He was an angel and changed my life and the lives of everyone he met."

Ryan defended the 10 cosmetic surgery procedures he performed on Montag as a "very well-thought out, calculated career move."

"Celebrities in the public eye need to look good," Ryan told HLN's "Showbiz Tonight."

"That's all there is to it."

The list of procedures Ryan did on Montag, a star of MTV's "The Hills," included breast implants, a nose job, Botox in her forehead, a brow lift, fat injections in her cheeks, a chin reduction and liposuction.

"No one needs elective cosmetic surgery; that is something that they desire," Ryan said. "That is what Heidi desired."