Worker missing after

A worker is missing after a “violent explosion” at a chemical facility in Massachusetts early Thursday morning, CBS Boston reported.

Firefighters were called to Seqens, a pharmaceutical manufacturing company in Newburyport, at about 12:45 a.m., the fire department said. When they arrived, they found an industrial-sized vat that had been inside the building was now about 30 feet away in a parking lot.

The fire department said there were five workers in the building at the time of the explosion. Four were taken to a hospital, treated and released. The fifth worker has not been found yet.

“We’re still searching for him,” Newburyport Fire Chief Steve Bradbury said at a news conference, adding that they’re “in a recovery mode.”

The explosion, which Bradbury called “violent,” caused major structural damage to the building so firefighters and technical rescue crews haven’t been able to go inside. The Coast Guard sent in their helicopter to help in the search but did not find anything.

“We need to make sure it’s safe for us to continue our search in a particular area that we want to take a look at,” the chief told reporters. “It’s going to be very methodical in nature for the protection of all the workers, the emergency workers that are here right now.”

Authorities said there’s no danger to people who live in the area. There’s no word yet on what caused the explosion.

This isn’t the first fire at this facility. Three years ago, there were six explosions that tore through the roof of the building. No one was hurt in that incident. The deputy fire chief at the time said the roof is designed to blow open to relieve any pressure that builds up. At the time, the company believed it was a mechanical issue from a steam line that caused those explosions.

According to the company’s website, Seqens has more than two decades of experience in chemical manufacturing and has two locations in Massachusetts.