WSOC has learned that Jackson Musyoka, of Flower Mound, Texas, is the driver who was trapped for nearly four hours inside his tractor-trailer Thursday on Interstate 85.

Firefighters and rescuers worked in the heat and in poison oak for hours to save Musyoka, who officials said lost his leg in the crash.

They feared he would die, but reassured him the whole time that he would be OK.

>> Read more trending stories

WSOC learned Musyoka's wife was on the phone with him when the crash happened.

"That was the worst ever, just to hear all of that," Tyshell Musyoka said, adding that her husband looked down for a brief moment while driving and when he looked back up the truck was swerving.

"I heard the tumbling and everything.  Then it got silent for a minute and then that's when I started hearing him screaming for help," she said.

He had no idea his wife was still on the phone, listening and worrying, until rescuers arrived. His wife heard their voices.

"The way they were doing him it pretty much eased my mind," she said.

Tyshell Musyoka couldn't hear everything, but she heard rescuers asking for room just as they got him free. J's ackson Musyokacell phone battery died before they took him out. She didn't get to hear them taking him up to a waiting helicopter.

"I just want to say, Thank you so much,'" Tyshell Musyoka said.

Tyshell Musyoka said her husband is weak, but in good spirits.

Police are still not sure what caused the 18-wheeler to go off the interstate.

Fireman shares his rescue story

Fireman Alex Hardee worked side-by-side with other rescuers.

"Four hours for me. That’s a first,"  Hardee said. "That’s the longest that I have probably been a part of," Hardee said.

Authorities said the trucker’s leg was so badly damaged, paramedics considered amputating it on the scene.

Hardee climbed into the rig in full turnout gear on a blistering hot day.

"Your body temperature, no matter how much you sweat, you can’t drink enough water," Hardee said.

Fire crews took turns so that they didn't overheat, going up and down a steep hill.

Cables from a large wrecker kept the truck from sliding further down hill.

"We have a job to do. We signed up to do this. We trained for this," Hardee said, adding for four hours firefighters and police focused on the trucker trapped inside.

"Keeping him abreast of the steps were taking to extricate him. Just more or less talking to him and keeping him calm," he said.

They had to remove the floor of the rig to pull him out. Hardee helped to take him back up the hill to a waiting medical helicopter.

"We were excited. We were glad that he was out. Then we got right back into the mode of, ‘We got to get him out of here,’" Hardee said.

They saved his life, but the damage to his leg was too severe. Doctors at the hospital amputated his leg. One officer said it’s still a success and that in 29 years he has never had rescue last so long and have the patient survive.