HERMON, Maine — Carol Miller, who has worked at Robert J. Bennett Wholesale Florist for the last 20 years, closed and locked the Odlin Street business’s doors at 3:30 p.m. Friday and left for the day.

Within an hour, she got a call that the building was ablaze. When she arrived back at work, flames were gutting the wholesale florist’s metal warehouse, turning it into a massive glowing red oven.

“We can’t even imagine what started it,” she said while standing in the parking lot at around 5:30 p.m.

Heat from the blaze warmed the evening air as scores of firefighters from Hermon, Levant, Newburgh, Glenburn, Carmel, Hampden and Bangor fought the blaze. A Maine Air Guard tanker was on hand to provide water.

But there was little firefighters could do. The building was in flames when they arrived, said Eion Pelletier, a Hermon firefighter-EMT who served as the scene commander. Their job at that point was making sure the raging fire, which at times shot 30- to 40-foot flames into the air, didn’t spread to the woods behind the warehouse, he said.

Thick black smoke from the fire could be seen for miles as firefighters sprayed the roof of the building.

Fred Robertson, owner of Fred Robertson Seal Coating of Orrington, was working on the parking lot at around 4:15 p.m. with employee Kevin Malloch when both got a whiff of something burning.

“I smelled it,” Malloch said. “Then I happened to notice a little spot on the wall” where the fire had broken through the outer wall.

Both men, thinking that the florist’s owner was inside the building because his car was in the parking lot, tried to alert him, but the door was locked. When no one responded to their banging on the door, Robertson called 911 and Malloch went to a neighboring paint store to inform them.

“Luckily, I was not” in the building, owner Robert Bennett said from the parking lot at 5:45 p.m. as he watched flames eat his company’s inventory. He said he got a call from an employee of the paint store, informing him of the fire.

“It’s a total loss,” Bennett said without giving a cost estimate for the damage. Bennett said he does have insurance, but added that he was in total shock and not sure what he would do next. “It changes your life.”

His father started the wholesale florist business 40 years ago and moved it to its current Odlin Street locale about 15 years ago, he said.

The structure housed “anything for florists,” Bennett said, “from flowers in the flower cooler to glass vases, shipping boxes, packing materials, offices, computers.”

Miller said the wholesale florist, which employs eight people, provides goods and services to retail florists “all the way to Madawaska, over to Greenville and down to the coast. We service a lot of people.”

“I’m just thankful nobody was in there,” she said, staring into the glowing warehouse.

Firefighters remained at the scene late into the night. Investigators from the State Fire Marshal’s Office were expected to examine the scene to determine the cause.

No injuries were reported as of 9:15 p.m., Pelletier, who was still at the scene, said by phone.

Investigators from the State Fire Marshal’s Office were at the scene Friday night trying to determine the cause, and were expected to return Saturday morning, Pelletier said.