Investigators continue to look for what caused a destructive fire and explosion at the Parker Lord manufacturing plant in Saegertown on Sunday.

For now the plant, Saegertown's largest employer, with about 220 workers, remains shut down.

Saegertown firefighters and surrounding mutual aid companies first responded to an automatic fire alarm just after 10:30 Sunday morning.  Shortly after they arrived, a massive explosion rocked the plant and the entire neighborhood causing extensive damage.

Saegertown Borough Manager Chuck Lawrence, also a firefighter, was in a rescue truck at the plant gate when the blast occurred. "When it blew, it shook everything in town, it shook my truck and it was just a total explosion the whole building was on fire," he said, adding that with first responders already inside, he feared the worst.  "I knew the guys, we had two trucks in there we had an interior crew plus the surrounding ones. I'll be honest with you - honest to God I thought they were dead," Lawrence said.

Four firefighters already inside the plant were hurt, blown back by the explosion.  They needed hospital treatment for cuts, bruises and an eye injury, along with four company employees who were also taken to local hospitals to be evaluated.

According to Christopher Farage, a Parker Vice President, all of the employees and firefighters as of Monday morning had been treated and released. 

At the Saegertown American Legion hall, right across the road from Parker Lord, staff and members heard the plant was evacuating and thought it was a routine drill until they saw smoke and flames, among them Chris Deets who caught the blast on his cell phone. Bartender Hannah Fox shared her experience.  "Then people started going toward the windows and you could see the flames above the building and that's when Chris started recording the fire and the explosion just happened while he was recording and everything moved, everything on the bar moved, you were kind of jolted backwards, it was just, it was intense," Fox said.

She also feared the worst and had to evacuate the American Legion. "When we evacuated here and I drove by and actually saw it on the way to my house, I said out loud  -- people had to have died -- you know it was, it was awful," Fox said.

At last word there was no power inside the plant.  It's unclear how long it will be closed.

The Parker Lord Saegertown facility makes coatings and adhesives used in the aerospace, automotive and oil and gas industries.  It's unclear how long the plant will be closed.