Acela train kills two teens

3:40 p.m. Update: Authorities say the two victims were teenagers, according to an Associated Press report. Interboro School District Superintendent Nancy Hacker says the two girls were sophomores in the district. A third girl was with them at the time and reported the accident, the report said. Their names have not been released.

2:15 p.m. Update:Amtrak reports that all four tracks have reopened and trains are traveling at normal speed but passengers can expect delays for awhile.

1:50 p.m. Update: Washington businessman Raul Fernandez was travelling on the train and said it came to a quick halt.

"The train slowed down quickly and came to a stop," Fernandez said in an e-mail. The businessman is a member of the Ted Leonsis group that owns the Washington Capitals. "They [Amtrak] told us we hit something and we had to wait for a rescue train. They never told us we hit two people. It's very tragic and sad."

-- Thomas Heath

12:50 p.m. Update: Most of the restrictions remain in place. The latest on service disruptions is available on Amtrak's Web site. We'll update as soon as we have more information.

Amtrak is reporting that two people were struck on the tracks nine miles south of Philadelphia's 30th Street Station by Acela train 2151, which runs from Boston to Washington, DC, via New York and Philadelphia.

A hold was placed on all four tracks at 10:38 a.m. Amtrak said, which means big service disruptions in the corridor. At 11:26 a.m., one track was reopened at restricted speeds.