A woman was killed in a seven-vehicle collision on Highway 4 in Pittsburg on Wednesday.

The collision occurred in westbound lanes of the highway near Harbor Road and Railroad Avenue, at around 8 a.m. Traffic on the highway had slowed in response to an earlier collision with no injuries between a motorcycle and a sedan.

One of the vehicles which slowed was a Nissan Sentra, which was then struck from behind by a Chevrolet Tahoe which had not slowed down. The Tahoe then lost control and rolled over, striking five more vehicles in the process, including a Dodge truck, an Audi sedan, a Toyota Highlander, a Chevrolet Trailblazer, and a Honda Civic.

The driver of the Nissan Sentra was pronounced dead at the scene. She has been identified as Theresa Frazier, 46, of Discovery Bay.

Several other people were injured in the crash, including a male passenger of the Nissan, and a man and woman in the Tahoe. All suffered serious injuries which were not believed to be life-threatening.

A boy in the Tahoe was also taken to a hospital as a precaution, but was apparently uninjured. None of the injured parties have been publicly identified.

The collision remains under investigation, and authorities are unsure what caused the Tahoe SUV to lose control. It is possible that the Tahoe was traveling at an unsafe speed, but it is unclear whether alcohol was a factor.