UPDATE: Driver Likely on Drugs, Sleeping at Wheel in Deadly Murrieta Crash, Police Say

UPDATE 8:54 p.m.:

MURRIETA, CA- A homeless teenage girl is dead and her sister hospitalized Friday following a major traffic crash in Murrieta this week which police blame on drug use.

The tragic crash happened around 7:45 a.m. Thursday, along Jefferson Avenue north of Juniper, according to Murrieta Police Sgt. Jay Froboese.

"The driver, a William Patrick Causer, 36-years-old, stated he fell asleep at the wheel drifting off the roadway and striking a telephone pole at approximately 45 mph without any pre-impact braking," Frobroese said in a news release Friday.

Causer's girlfriend, identified as 34-year-old Rebekah Joy Davis, was in the front seat, and her two children were in the back, according to the sergeant. Both adults were wearing seatbelts. Neither child was.

"[Davis'] 15-year-old female child sustained fatal injuries in the collision and her 10-year-old female child is currently in critical condition in the hospital with major internal injures," according to Frobroese.

The girl was identified Friday by the coroner's office as Summer Carbone, from Rialto.

However, all four involved in the crash were without a home, and had been living out of the vehicle involved in the wreck, according to the sergeant.

The two adults remained hospitalized as of Friday evening, but police say they are both facing arrest once released.

"Upon release they will be charged with multiple felonies related to this collision," the sergeant said. "Drug use and driving under the influence of drugs is suspected in this collision based on investigators initial observations of Causer and Davis."

Police are currently looking for anyone who may have spotted the vehicle— a green Dodge Caravan— driving in the city of Murrieta between 7:30 a.m. and 7:45 a.m. Thursday. Those with information are asked to contact Investigator Stickleman at 951-461-6306.

ORIGINAL STORY AS FOLLOWS

MURRIETA, CA - A 15-year-old girl was killed in a vehicle crash in Murrieta, coroner's officials reported Friday.

Summer Carbone of Rialto was injured about 7:45 a.m. Thursday on the sidewalk on Jefferson Avenue, 80 feet south of Town Square, according to the Riverside County coroner's office.

Carbone was pronounced dead about 45 minutes later at Rancho Springs Medical Center, the coroner's office reported.

It's unclear if she was on foot or in a vehicle when she was injured.

A Murrieta police watch commander referred questions to a traffic sergeant who was not immediately available.

Patch will update this breaking news story as more information is learned. Refresh for the latest.

– City News Service contributed to this report. Image via Shutterstock.