BURLNGTON, Mass. — Massachusetts State Police are looking for the vehicle that was carrying a mattress that fell onto Route 128 south in Burlington, causing a rollover crash that fatally injured a motorist.

The crash involving a Toyota Corolla and a Toyota Tundra occurred at about 3 p.m. Tuesday and shut several lanes of southbound traffic for more than an hour. One motorist, a 56-year-old Framingham woman, died from her injuries at Lahey Hospital.

Police believe the Corolla was rear-ended by the Tundra when it slowed to avoid hitting a twin-sized mattress in the roadway. The collision caused the Tundra to roll over.

Authorities are seeking a dump truck with a white cab and a dark-colored bed. At the time of the crash the dump truck was said to be occupied by two men.