One person was dead and six injured in a car crash on Southbound I-880 in San Leandro early Saturday morning. Photo courtesy of Alameda County Fire Department 

SAN LEANDRO — One person was dead and six others injured in a multicar crash early Saturday morning on I-880, near the Floresta Blvd overpass, according to a California Highway Patrol officer and the Alameda County Fire Department.

At about midnight a driver northbound on I-880 re-ended another car, causing the second car to overturn, according to CHP Officer Dustin Kennerly.

The driver of the first car was arrested for driving under the influence, Kennerly said, but the driver of the second car was not at the scene. It’s unclear how that driver left or if they were transported to a hospital before CHP officers arrived on the scene.

At some point, a Good Samaritan stopped and got out of their car to help, according to a preliminary investigation. That person was struck and killed by another car, Kennerly said. Two other people were injured and transported to hospitals with injures that were not life-threatening, Kennerly said, but the sequence of events that led to those injuries is still unclear.

The crash was considered a mass casualty incident, the fire department said in a tweet. Two people were ejected from their vehicles in the crash, and patients were transported with moderate to severe injuries to the Eden Medical Center in Castro Valley and Highland Hospital in Oakland.

The incident is being investigated by the California Highway Patrol.

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