BOSTON (CBS) – A National Grid truck driver is facing criminal charges in a crash that killed a Westford grandmother.

In August of 2011, a backhoe being hauled by the truck came loose and crushed a minivan driving on I-495 in Southboro.

A clerk magistrate has now decided there is enough evidence to charge the driver, Jeffrey Fisher, with motor vehicle homicide.

National Grid admits it was test driving the truck because of safety concerns.

The victim’s daughter and two grandchildren were also hurt and the family has filed suit against National Grid.

Fisher will be arraigned on August 20.