Yesterday, officials detected a spike in vinyl chloride fumes and issued a “shelter-in-place” order for the town of Paulsboro, just across the Delaware River from the Philadelphia airport. The order was for people to stay indoors until the gas fumes had dissipated. Though levels dropped, this morning the order was still in place.
Train cars carrying vinyl chloride derailed last Friday while crossing a Paulsboro bridge. One car spilled its vinyl chloride load into Mantua Creek, a tributary to the Delaware River. Vinyl chloride is a known carcinogen for humans. Many people were treated for symptoms from the chemical exposure, but there were no fatalities.
The train came to a stop before the Paulsboro bridge because the red light was on, indicating it was not safe to pass. When the light did not change, and it became clear there was no cross traffic, train engineers contacted the switch operator and asked for clearance to proceed, despite the red light. Clearance was given. The train crossed the bridge at a slower pace than usual- 7 mph instead of 10 mph. During the crossing, the emergency brake engaged as the bridge collapsed, sending four cars into the water.
According to the Philadelphia Inquirer, the go-ahead from the operator in Camden was the largest of several errors that contributed to the accident. The bridge had been reported earlier for failing to reset properly after a train crossing, which is why the red signal was on. The Camden operator was unable to change the signal from red to green. Red indicated that the train rails were not locked in alignment with the rails on the farther shore. The operator gave the Conrail freight train permission to cross despite the red signal. There used to be a bridge operator, but now the crossing is automated. Add to that the fact that some of the bridge parts date back to 1873 (although it has been repeatedly rebuilt after previous accidents), and there’s a recipe for disaster.
According to the National Transportation Safety Board (NTSB), the bridge had been reported for trouble 23 times over the last year. NTSB Chairwoman Deborah Hersman called for a national focus on improving the integrity and therefore safety of the country’s infrastructure.