Amtrak's Acela 2173 was traveling southbound when it was hit on the left side between 9:05 and 9:10 p.m., about five minutes before it entered 30th Street Station, according to 29-year-old passenger Madison Calvert.
"I just thought somebody might have thrown something at it," said Calvert, who was sitting beside the window that was hit. "I had no idea. The window didn't break through. But it shattered."
Calvert said once at 30th Street Station, Amtrak police boarded the train, documented the damage and decided it was safe for the train to continue. Calvert said he heard about the train about five to 10 minutes later.
Kam Desai, one of Calvert's coworkers who was also on the train, said the sound of the impact was "huge."
"It was really loud," he said. "It's pretty thick glass. For it to get shattered, at that point it's pretty hard impact."
Another passenger on the train, who asked to not be named, said he thought the train was hit at about 9:09 p.m. in the vicinity of St. Christopher's Hospital, which is located at Whitaker and Erie avenues, less than two miles from the site of the derailment.
SEPTA northbound Train 769, en route to Trenton on tracks on the Northeast Corridor beside the Amtrak rails, was approximately four miles from the derailment site when it was struck at about 9:10 p.m. SEPTA spokeswoman Jerri Williams said an "unknown projectile" broke the engineer's window.
No injuries were reported and the train was held on the tracks ahead of the North Philadelphia station. The 80 passengers were transferred to buses.
Amtrak's northbound Train 188 derailed on the Northeast Corridor tracks, killing at least seven and injuring scores. The cause of the derailment is under investigation by the National Transportation Safety Board and the Federal Railroad Administration.