Team Coverage by Al Novack, Walt Hunter, Steve Beck, Mike DeNardo, Lynne Adkins, and Kim Glovas

PAULSBORO, NJ (CBS) — A freight train derailment resulted in a chemical spill Friday morning in Paulsboro, NJ, sending dozens of people to area hospitals.

Officials say a Conrail freight train derailed over Mantua Creek at about 7 a.m., leaking a chemical called vinyl chloride. In total, the train had two locomotives and 84 cars. Officials say seven cars were derailed; two on land and five on the bridge with four of those cars going into the creek. One of the derailed cars was compromised. Hazmat crews responded and limited evacuations were ordered.

Officials put a new evacuation order in place around 7 p.m. About 500 residents within a 12-mile radius of the accident scene are affected. Authorities say those residents were told to pack for three days and were then transported to local hotels.

Officials say Conrail has established a public assistance center at the Paulsboro Fire Department in the 1500 block Swedesboro Avenue. Representatives will be available to assist with any issues that have arisen due to the crash and resulting spill. It will be open from 8AM to 7PM.

VIEW: Photos From The Scene

An environmental company responded by CSX to place booms in the creek and the Gloucester County HazMat Team and HazMat Team from PRC Refinery were doing metering and monitoring.

Earlier Friday morning, Paulsboro public information officer and Assemblyman John Burzichelli said that as of 10:30 a.m., all of the vinyl chloride in the compromised car has dissipated and Conrail has put together a plan of attack that includes crews working on the ground and via barge with a crane.

Officials say it appears the cars derailed when the bridge they were traveling over buckled. This is not the first time the bridge has failed. In 2009, it collapsed and had to be rebuilt.

WATCH: 10:30 a.m. News Conference Update
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WATCH: 3:00 p.m. News Conference Update

The New Jersey Department of Transportation says it is postponing the weekend closure of the Route 44 Mantua Creek Bridge because of the train derailment. Instead, the Mantua Creek Bridge will remain open to traffic.

NJDOT had planned to close the drawbridge for three weekends for maintenance repair work. The department says it will notify the public when the work is rescheduled.

The County Office of Emergency Management had issued a shelter in place activation and school children were sheltered in place in Paulsboro; East Greenwich; and West Deptford. Shelter for displaced residents was set up at the high school.

Burzichelli urged the community to be cautious and to pay close attention to public announcements throughout the day. A reverse 911 system is in place to make calls to residents with updated information as is becomes available.

Officials said water and air quality in Paulsboro was at acceptable levels and safe.

READ: More Facts About Vinyl Chloride

Rescue units were dispatched to the scene after numerous people complained of respiratory problems. A total of 71 people, including some children, sought treatment at Underwood Memorial Hospital in Woodbury.

Vinyl chloride is used in the making of plastics, according to Dr. Charles Haas, a professor of environmental engineering at Drexel University. He says that in the short term, the danger is the chemical gets into the air and causes irritation to people.

“Irritation to both the respiratory tract and eye irritation, (and) perhaps some short-term breathing problems,” he tells KYW Newsradio. In the long term, he said vinyl chloride is known to cause cancer.

“All steps are being taken to provide and ensure the safety of this community,” said Burzichelli.

The National Transportation Safety Board has taken over the investigation. Their team of 17 will investigate the cause of the accident and issue recommendations to prevent this from happening again.