Four workers were found, but one remains unaccounted for following a chemical explosion at an industrial park in Newburyport, Massachusetts, early Thursday.

Authorities first received reports of the explosion at 12:45 a.m., according to a press release from the Newburyport Fire Department.

The four workers who were inside the building were taken to the hospital, treated and later released, the fire department said. Authorities are continuing their search for the fifth worker.

An "industrial-sized vat" that was previously inside the building moved approximately 30 feet as a result of the explosion and was found in a parking lot next to the building, the fire department said.

The building sustained major structural damage as a result of the chemical explosion, and there is no danger to the public at this time, according to the fire department.

This is a developing story. Please check back for updates.