ESSEX (CBS) – A fire that tore through a popular seafood restaurant in Essex, just hours after a busy day of takeout orders, was caused by a gas heater left running overnight, investigators said.

Flames broke out in the kitchen at Essex Seafood on Eastern Avenue around 11 p.m. Sunday. No one was hurt, but it took firefighters about an hour to get the fire under control.

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Essex Seafood the morning after a devastating fire there, May 11, 2020. (Photo credit: Anna Meiler – WBZ-TV)

“The fire originated over the counter area where there was a 15-20 year old ceiling mounted gas heater. The heater had been left running overnight after the restaurant closed,” the State Fire Marshal’s Office said in a statement Monday.

Damaged is estimated at $250,000. The building inspector said it is “probably a total loss.”

Howie Lane said he watched in disbelief as the restaurant he’s owned for 22 years went up in flames.

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“At one point I broke down and I’m a pretty strong guy,” he told reporters. “We got 22 years in this, our heart and soul, and look it’s just burning.”

They were busy filling orders all day Sunday.

“We actually had our busiest Mother’s Day that we’ve had, but then it ended up being our worst Mother’s Day,” Lane said, adding he will rebuild the popular clam shack. “I’m looking forward to getting my hands dirty and tearing it down and getting it back up.”

Bruce Conrad lives in the house directly in front of the restaurant. Police woke him up in the middle of the night and told him he needed to get out fast.

“Flames were coming out of the front door and the roof,” Conrad told WBZ-TV. “It’s a double roof so it’s hard to put out. They had to cut several holes in the roof.”

Flames tore through Essex Seafood late Sunday night. (WBZ-TV)

Brianna Pappas has lived next door to the restaurant for 16 years and worked there for two summers.

“It was definitely really sad especially since I have a lot of personal memories with my co-workers there. A lot of long nights, sweating hard, working together, but at the end of the day we were doing a good thing for the town, providing the town money and serving these people who have been coming their whole lives so I can’t even imagine how devastating it will be for them as well,” she told WBZ.

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“To get woken up at midnight last night knowing it was in flames didn’t seem real. It’s a shame, it’s a shock, beginning of the season too,” said Pappas’ father James.