An off-duty Los Angeles police officer is in serious condition after being struck by an SUV while riding his motorcycle in Fullerton.

The crash happened on Commonwealth Avenue at Basque Avenue about 10:50 p.m. Monday, said Fullerton police Sgt. Jon Radus.

The rookie officer, whose name was withheld, has been working for the LAPD for less than a year and was assigned to the department's Wilshire station, according to Officer Mike Lopez of the LAPD.

The driver of a 2005 Toyota Sequoia was trying to make a left turn onto Basque when her SUV struck the officer's Harley Davidson motorcycle, police said.

The 24-year-old was transported to UCI Medical Center to be treated for serious head and leg injuries.

Radus said the SUV driver, a 19-year-old woman, was not injured and not at fault, and neither alcohol nor drugs appeared to be factors in the crash.

He said she remained at the scene and cooperated with the investigation.

Neighbors told CBS2/KCAL9's Stacey Butler that she was weeping on the side of the road as medics helped the officer lying on the ground.

"His leg was pretty much really bad. And he was bleeding a lot. And he was like unconscious. Little bit more sad because he's a young guy, and he had to go through something like that" said Frankey Hernandez.

The injured officer is expected to have a long recovery.