CHARLOTTE, N.C. >> Crews searching the rubble of a massive construction fire in North Carolina today found the bodies of two people who firefighters couldn’t reach to save before the flames became too intense.

Authorities didn’t identify the victims, but officials said two workers were missing after the Thursday fire on the site of a new apartment building in the upscale South Park neighborhood of Charlotte.

No one else was injured in the five-alarm fire, including more than 90 firefighters and a worker trapped for a time on top of a crane as a fire engine sprayed water on the metal to keep it from collapsing.

“I’ve never ever seen a fire of this magnitude,” said Charlotte-Mecklenburg Police Chief Johnny Jennings, a 31-year veteran of the force. “It’s devastating, heartbreaking.”

Investigators think the fire started about 9 a.m. Thursday in a trailer used to spray insulation into the building’s walls, Charlotte Fire Chief Reginald Johnson said.

The chief said they aren’t sure exactly what set off the blaze and haven’t been able to do a thorough investigation of the trailer.

“Obviously, the building’s still in a state where it is not safe for all of our members to go in,” Johnson said.

The massive fire sent huge red flames and dense black smoke into the sky. At least two small crews of firefighters had to make mayday calls and be rescued from the fast-moving blaze, including one who could hear the cries of the trapped people on the sixth floor but couldn’t see them through the smoke, Johnson said.

“They were going by sound, trying to get to them but were unable to get to them before conditions changed,” Johnson said. “They had to call a mayday.”

The firefighters did rescue 15 workers inside the building, including the crane operator. Firefighters delivered protective clothing to him until he could climb down to safety, Johnson said.