Morehead City Mayor Jerry Jones says the material is a chemical commonly known as PETN, but it's not clear what form it was in. The Morehead port was shut down and people near it were urged to leave. No one was hurt.
PETN is the substance authorities say was part of a device a Nigerian man tried to use to bring down a Detroit-bound Northwest flight on Christmas Day.
But Jones says the damage Tuesday appeared to be an accident and there were no concerns about terrorism.
North Carolina State Ports Authority spokeswoman Karen Fox says she does not know where the shipment originated or where it was headed.
