A Massachusetts police officer and a National Grid worker have died after being hit and killed at a construction detail in Waltham.

Middlesex County District Attorney Marian Ryan says the crash happened around 4 p.m. on Totten Pond Road.

Ryan says the driver, 54-year-old Peter Simon of Woodsville, New Hampshire, allegedly hit a jeep while trying to do a u-turn. Simon reportedly continued driving and hit 58-year-old Waltham police officer Paul Tracey and a 36-year-old National Grid worker from Cambridge, whose name was not immediately released.

Both of the victims were working at a construction site at the time of the crash and died from their injuries.