SAN DIEGO -- A Marine and a woman died Saturday in a chain-reaction crash on a highway north of Escondido, in which one driver may have fallen asleep and another may have been drunk, according to the California Highway Patrol.

Kyle Cohen, 29, of Chula Vista, was driving north on Interstate 15 near the Gopher Canyon Road onramp, north of Escondido, at around 4 a.m., when his 2001 Volvo sedan rear-ended a Jeep Cherokee carrying four Marines, said CHP Officer Eric Newbury.

Cohen said he had been sleepy, the CHP officer said.

The Jeep, which was driven by Aaron Lowden, 20, a Marine stationed at Twentynine Palms, spun out and stopped on the right shoulder, partly blocking the right-most traffic lane, Newbury said.

As the Marines looked at the disabled Jeep, a 2001 Chevy Cavalier driven by Oscar Tinoco, 18, of Quail Valley, hit the Jeep, which knocked one of the Marines off the freeway overpass onto Gopher Canyon Road.

Tinoco, and a 17-year-old passenger fled. Next, Sarah Garcia, 21, of Fallbrook, struck the Chevy in her 2000 Jeep Grand Cherokee, which veered down the embankment, across the Gopher Canyon Road onramp, vaulted a guardrail, rolled down another embankment and came to rest on its wheels, according to Newbury and the coroner's office.

Garcia died at the scene.

The injured Marine was taken to Palomar Medical Center, where he was pronounced dead shortly after arrival. His name was withheld pending notification of his family.

Lowden and his two other passengers, Joshua Naimi, 29, and Robert McBee, 20, were also taken to Palomar Medical Center and treated for minor injuries.

Tinoco and his teenage passenger were caught by CHP officers as they ran from the scene.

Tinoco was booked into the Vista Detention Facility on suspicion of felony drunken driving, gross vehicular manslaughter and felony hit and run.

His passenger was taken to Palomar Medical Center and treated for minor injuries.

Northbound Interstate 15 from Gopher Canyon Road was shut down for more than five hours as CHP officers investigated the crash.