The National Transportation Safety Board continues to investigate the collapse of a rail bridge in Paulsboro at the end of last week that led to a 7 car train derailment and the release of a hazardous chemical vapor.

2 tanker cars in Paulsboro train derailment (Twitter)

Dozens of people were taken to the hospital, and more than a hundred local residents were evacuated late Friday, because of concerns that more vinyl chloride gas could seep out of tanker cars that had tumbled off the tracks and into a creek.

State Senate President Steve Sweeney says, "Nobody is accusing anybody of anything, but Conrail was aware of a possible problem with the bridge…We've been told they were out there - I originally thought it was for a couple of weeks, they said they've been looking at the bride for about a month."

He says, "We gotta get some answers. The frustration is this happened 3 years ago - the same bridge was rebuilt and now people were alerting Conrail to their concerns - Conrail didn't ignore them, but we gotta get some answers on it cause these chemicals can cause great harm….The safety of the residents is key."

Sweeney adds it's no secret that "the rail infrastructure in this region is in trouble - it really is in bad shape - we just were successful in getting a grant of 18 million dollars from the federal government to start to update our rail system…Some of the trains in South Jersey are forced to go 5 miles an hour because the rail was laid in 1908 and if it goes any faster they derail, so I think there's going to be a lot of discussion on how we update our rail system."

"This rail carries a lot of volatile, volatile chemicals and you know it's a trade-off, there's a lot of very good paying jobs on the other end of these stops - in these refineries and these plants…But the thing that really has to be drawn is the safety of the rail system in the region and the state - we know we have a problem- how do we improve it? Thank God no one was seriously injured here - but that doesn't mean we can't address the issue."