(CNN) Forty-two people were injured when an incoming high-speed train struck an unoccupied train car inside an Upper Darby, PA, transit terminal early Tuesday morning, Upper Darby Mayor Thomas Micozzie.

Four people, including the train's conductor, were rushed to area hospitals, Micozzie told local media at a news conference near the crash site.

The incident occurred at approximately 12:15 a.m. ET at the 69th Street Terminal and is currently under investigation, according to Southeastern Pennsylvania Transportation Authority (SEPTA) spokeswoman Heather Redfern.

Video from CNN affiliate KYW showed police, fire and EMS services at the scene as onlookers gathered.

Mayor Micozzie: "An inbound Norristown high-speed train came into the terminal and hit a stationed car."https://t.co/LVsosPjrj8 pic.twitter.com/9xKIFL0HbV — CBS Philly (@CBSPhilly) August 22, 2017

The Norristown High Speed Line runs between the 69th Street Terminal and Norristown.