An investigation is underway in Bristol after an Amtrak train struck and killed three people Thursday evening, according to police, media reports and bystanders. Bristol Police Chief Joe Moors said that a sergeant responding to a call for someone on the train tracks was en route when the three were struck and killed by an Acela train.

Amtrak service between Philadelphia and New York was halted for hours Thursday evening after three family members were fatally struck by a train near Bristol Station in Bucks County, Pennsylvania, officials said.

A father and outreach coordinator who worked in social services in Bucks County and his two adult sons died when a speeding Amtrak train crashed into them in suburban Pennsylvania Thursday night.