A commuter train slammed into the rear of another during rush hour near Boston today, killing the operator of one of the trains, the Boston Globe reports. The victim, a 24-year-old woman, had been on the job less than a year. The cause remains unclear, and one person is still hospitalized. The accident follows a derailment this morning in Chicago that injured 14 and was blamed on human error—a motorman went through a stop signal. (More Boston stories.)