It could be a few more days before crews finish clearing derailed train cars — including crude oil tankers — from a bridge over the Schuylkill River in Philadelphia.
After a string of more serious rail accidents involving crude oil in other parts of the country, the incident has amplified local concerns about safety.
It was one of several trains that bring tens of thousands of barrels of crude oil from North Dakota to a refinery in South Philadelphia every week.
The cause of the derailment is still being investigated, but Philadelphia Mayor Michael Nutter says for now, the city is safe.
"For us at least, derailments are fairly uncommon, but I'm sure there's always something that we can take a look at or focus on," Nutter said. "You can never be too cautious or too careful, so we'll see what comes out of this investigation."
However, there are others who say Philadelphia dodged a major bullet.
"We came within a hair's breadth of a calamity in Philadelphia," said Democratic gubernatorial candidate John Hanger. He has joined the chorus of environmental groups and local lawmakers calling for more information as shipments of crude oil continue to roll through populous areas in Southeast Pennsylvania.
Seven of the train's 101 cars slid off the tracks, but remained intact. Some of the cars are still leaning across the bridge over the Schuylkill River.
Hanger says Philadelphia was lucky compared to other communities where derailments have resulted in explosions
"People's lives are at risk. That's the bottom line. People's lives are at risk," he said.
He wants Gov. Tom Corbett to hold an emergency meeting with lawmakers, the railroads and the oil industry.
Hanger and others are pushing to replace current tank cars with ones less likely to rupture during an accident.