A construction worker pleaded for help on Facebook Live before he died in a construction site fire in Charlotte, North Carolina, family members told CNN affiliate WSOC.

Demonte Sherrill, a 30-year-old father of four, was among the 15 working at the site, Charlotte Fire Chief Reginald Johnson said in a news conference.

Sherrill's mother, Onita Sherrill, told the station she watched the final moments of her son's life on a Facebook Live with him pleading for help and praying he would find a safe space.

"I was hoping but just from the (Facebook Live), and the way the room filled up with smoke, I didn't see it being any hope at that time," she said.

His father, Terry Campbell, said his son's boss told him Sherril did not make it out alive, the station reported.

The contractor who employed Sherrill told WSOC Friday another worker from his company died in the fire.

Authorities have not confirmed any deaths.

"The search process can be lengthy," the Charlotte fire department tweeted. "We can not confirm a loss of life. This fire has been difficult for our community, and our firefighters continue to diligently work on scene to find answers."

More than 90 firefighters worked to rescue the construction workers, Johnson said.

With heat above 2,000 degrees, the fire moved rapidly, he said.

Mayor Vi Lyles tweeted firefighters rescued a crane operator who was stuck above the blaze, which started around 9 a.m.

The building under construction was a multistory apartment building, WSOC reported.