All eastbound lanes of the 10 Freeway were closed in El Monte for eight hours Tuesday due to a homicide investigation, snarling traffic during the morning commute.
A tow truck driver called 911 after he saw that a woman behind the wheel of a disabled vehicle was unresponsive, according to officer Juan Galvan of the California Highway Patrol's Los Angeles County division.
Once fire officials arrived, they pronounced the woman dead at the scene, Galvan said. Investigators said the woman was in her mid to late 20s.
It was not immediately clear what led up to the woman's death, but CHP noted they were investigating the incident as a homicide.
"At some point, throughout the course of this incident, the white Chevy Malibu that we have here on scene on the right shoulder collided with the sound wall on the right shoulder and came to a stop where it is now," Galvan said.
The freeway fully reopened Tuesday afternoon.
