State Police report the death of Trooper Tamar Bucci shortly before midnight on the northbound side of I-93 in Stoneham.
State Police say Bucci was pulling to the side of the road to help a motorist in a disabled car when the driver of a gasoline tanker hit her cruiser.
The force of the impact pushed her cruiser, a marked Ford Interceptor SUV with its emergency blue lights activated, off the road.
Two civilian Good Samaritans pulled Trooper Bucci from the heavily damaged cruiser and a Stoneham Police Officer who came upon the scene performed emergency first aid, including CPR, until EMS arrived and transported her to Massachusetts General Hospital.
The tanker driver, not injured, is cooperating with the investigation.
Bucci joined the State Police in 2020.