BY KATHY MCCORMACK AND STEVE LEBLANC for the Associated Press

WALTHAM, Mass. (AP) — A pickup truck driver in a Boston suburb is accused of crashing into a police officer and a utility employee at a work site, killing both, then pulling a knife on another officer before stealing his cruiser and crashing, law enforcement officials said.

Two other utility workers were injured in the initial crash Wednesday afternoon in Waltham, about 10 miles (16 kilometers) west of Boston, and “multiple other vehicles” were struck by the truck before it was abandoned, Middlesex District Attorney Marian Ryan said in a news release. The two other workers were treated and released from the hospital.

“Clearly what happened … is an unimaginable tragedy,” Ryan said at a news conference. “These two men were doing their job at 4 o’clock in the afternoon when they were killed and crashes like this happen far too often.”

After the cruiser crashed, police said they arrested the driver after a brief foot pursuit.