A Boston trolley driver, who investigators say was sending a text message during an accident, has been indicted.

Aiden Quinn was indicted by a Suffolk County grand jury Wednesday on charges of grossly negligent operation of the train.

Nearly 50 people, including Quinn, were hurt when the trolley rear-ended another train May 8. The crash caused an estimated $9 million in equipment damage.

The Massachusetts Bay Transportation Authority fired the 24-year-old Quinn about a week after the accident.

Quinn's attorney did not immediately return a call seeking comment.