The derailment is being blamed on a defective bridge. Vinyl chloride sickened dozens of people, causing some to be hospitalized. Four tankers in the 84-car freight train spilled the vinyl chloride into Mantua Creek below the bridge. The creek flows to the Delaware River. More information below these videos.
Update: Late this afternoon, the cleanup is beginning. NTSB Chair Deborah Hersman surveyed the scene and indicated in a statement (video below) that there is "still some product" in one of the train cars "that needs to be removed" before the cars can be taken off of the ruined bridge. Hersman did not specify what the "product" was that she referred to, but she probably meant the spilled and leaking vinyl chloride.
The Associated Press (AP) reports that authorities say the train derailed "on an old-style swing bridge that apparently buckled, three years after a similar failure, toppling at least two tanker cars into a creek and causing a leak of hazardous gas blamed for sickening dozens of people." That "hazardous gas" was vinyl choride, "a gas that at high exposure levels can cause breathing problems and dizziness." Vinyl chloride is flammable, but there was no report of any fire at the scene of the derailment.
Vinyl chloride is very dangerous, notes the Courier Post Online, and is a known carcinogen, and can kill if it is breathed in high concentration. "It is technically possible for vinyl chloride to migrate into groundwater supplies," says Popular Mechanics, "although that seems unlikely, as the nearest drinking water intake is 20 miles upstream from the spill site, which officials have called a safe distance. Nevertheless, officials are testing the water supply of the town and have set up containment booms in the creek as a precaution."
|Derailed tank cars in Mantua Creek, Nov. 30, 2012 (NJ.com)|
"This is the same bridge that collapsed in August 2009," reports NJ.com, "as a 50-car coal train passed over it, spilling 16 cars into the water." The bridge was rebuilt in 2010.
Investigators from the NJ Department of Environmental Protection (DEP) are at the scene, assessing the damage. Although the vinyl chloride no longers poses an air pollution problem, reports the Courier Post Online, "DEP investigators are there now mainly trying to assess what the issues are with anything that may have leaked into the water from the two cars off the train bridge. He thinks one of those cars may be plastic pellets, so only one car may have leaked a chemical into the creek."