The Mystic fire chief says it could take days to determine the cause of a huge fire that destroyed two buildings in Mystic's worst blaze in over 20 years.

"This was really unbelievable. It was engulfed within 15 minutes. It happened really quickly," said Tom Oats, from Mystic.

Oats shared video with News 12 Connecticut of Sunday night's fire along the Mystic River at Seaport Marine.

Fire crews from several towns, even some from Rhode Island, came to fight the blaze that ruined a large storage and office building and badly damaged an adjacent home.

Oats, who used to work at the Norwich Bulletin, says he was thankful for the work all the fire departments did to prevent this from getting much worse.

"It was under control pretty quick. In terms of that, they had it surrounded they had the area closed off," said Oats.

"I stepped out on my porch to, like, my car and turned around, I thought the whole town was on fire," said Peter Fenn, from Mystic.

Another eyewitness, Fenn says he heard explosions.

"You saw balls of fire going up and a lot of it was obstructed by smoke. Yeah, there were flames like up 150-feet in the air," said Fenn.

People were forced to evacuate their homes.

Mystic Fire Chief Anthony Manfredi says strong winds spread the blaze, which officials believe may have started inside one of the buildings.

"There was some propane tanks inside, inside the property. They were exploding. The power lines had come down, burnt and come down," said Manfredi.

Seaport Marine is owned by the Holstein family, which just bought the property and recently sold its other marina in Noank. The family, including Harry Boardsen, also own Bridgeport Boatworks.

One firefighter was treated for minor injuries. Officials say no one else was hurt.

The Mystic fire chief is asking anyone who has early images of the fire to contact the Stonington Police Department at 860-599-4411.