That’s according to Don Jaquish, director of Essex County Emergency Services, which is also investigating the cause and origin of the fire. He said it was “definitely accidental,” but he can’t be sure of the cause until after the insurance company’s investigators do their work.

It’s a potentially dicey situation because if fault is found with the unit itself or its installation, the insurance company might pursue the manufacturer or installer for damages.

Jaquish and Brendan Keough, chief of the Saranac Lake Volunteer Fire Department, both said Tuesday night that it appears the fire started in the heating and air conditioning unit. That’s also what it looked like to people who watched flames and smoke spout from the unit in a second-floor room facing Lake Flower.

Bill Domenico of Saranac Lake happened to be standing on the opposite shore of Lake Flower on Kiwassa Road with his sons when they saw flames spout from the Saranac Waterfront Lodge. He guessed they might have been among the first people to see the fire.

Flames spout from the vent of a second-floor room’s heating and air conditioning unit Tuesday afternoon at the Saranac Waterfront Lodge in Saranac Lake. The hotel had opened just seven weeks ago. (Enterprise photo — Lou Reuter)

“There was a burst of flame from the same window that lasted approximately four seconds,” he said. “(The) blast was similar to what you’d envision a propane tank explosion to be like.”

The room was unoccupied and no one was hurt, but the hotel — which opened just seven weeks ago — was left with major damage to repair.

In addition to fire and smoke, there is serious water damage from sprinklers and firefighters’ hoses, according to Keough and Jaquish. Keough said he noticed a truck from a water damage remediation company already in the hotel’s parking lot Tuesday evening.

But the water also prevented what could have been a much worse fire, Keough said. While the sprinklers in the room couldn’t quite hit the flames in the exterior wall, they kept them from spreading.

“The potential was there for a catastrophic loss,” Keough said. “The whole structure is wood, lightweight wood frame construction. The sprinkler systems did their part, and luckily it wasn’t able to get to the floors above.”

While he described the damage as “heartbreaking,” he said the firefighters from Saranac Lake and Lake Placid made a good save, attacking the fire from both inside the room and from the outside.

“They really did a hell of a job,” he said.

He and other members of the fire department had just done a safety session with the hotel’s staff in November, as it was opening — its soft opening was Nov. 16 — and the training apparently paid off. The lessons of what to do in case of a blaze were fresh in everyone’s minds Tuesday.

“The hotel people, I will tell you, were phenomenal,” Keough said. “Their cooperation was phenomenal; they were super-responsive to our efforts.”

He was also happy with the turnout of firefighters: 26 members and three trucks from his squad and 20 more and one truck from Lake Placid, plus Paul Smiths-Gabriels firefighters standing watch at the Saranac Lake firehouse.

“At 1:30 on a work day with a volunteer group, you’re not sure how many will show up,” he said.

Village code enforcement officer Patrick Giblin was also on scene; the hotel staff will have to work with him on what needs to happen before it can welcome guests back. Jaquish said power was killed and the sprinkler disabled in the part of hotel where the fire occurred.

“They’re going to have to do a lot of work to get it back in order,” Jaquish said.