Federal transportation investigators have begun interviewing the crew of a train that was carrying hazardous materials when it derailed on a railroad bridge in New Jersey, officials said on Saturday.
National Transportation Safety Board Chairwoman Deborah Hersman said the agency would spend the next two weeks preparing a preliminary report on Friday's accident in the industrial town of Paulsboro.
A bridge collapse derailed seven of the 82 Conrail freight train cars, and a tanker car that fell into Mantua Creek leaked vinyl chloride into the waterway, which feeds into the Delaware River near Philadelphia.
More than 12,000 gallons (45,425 liters) of the highly toxic and flammable industrial chemical vinyl chloride leaked from a gash in the tanker car's side following the derailment on Friday morning.
Twenty-two people were examined at a nearby hospital, but air monitors in the area did not register any problem, officials have said. Exposure to vinyl chloride can cause a burning sensation in the eyes or respiratory discomfort.
Investigators were obtaining records from Conrail on inspections of the bridge over the Mantua Creek. They also examined a derailment on the bridge in 2009, as well as any possible impact on the bridge from the high winds and rising waters that accompanied superstorm Sandy.
"We are continuing to question the crew to get additional information," Hersman said at a press briefing. "We still have some work to do."
State Senator Steve Sweeney, whose district includes Paulsboro, told Reuters on Saturday that 106 residents who live close to the crash scene were evacuated from the area on Friday night in case any more of vinyl chloride escaped into the air or water.
"What it really was was just to be cautious," Sweeney said. The residents will be out of their homes for several days, and are staying with friends and relatives or hotels, he said.
Conrail is jointly owned by rail operators CSX Corp and Norfolk Southern Corp.
(This story corrects name of town in second paragraph to Paulsboro, not Paulson)
(Editing by Paul Thomasch and Bill Trott)