It happened on Woodburn Avenue off Highway 751.
It's believed 26-year-old Brad Roberts was cutting down trees in his yard when he fell out of one.
He was taken to Duke University Medical Center, but it was too late.
Roberts joined the Durham Fire Department on March 7, 2005 and was assigned to Fire Station #1.
"Our department is devastated today by the death of one of our firefighters, but the fire service is a very closely knit profession and we will support each other through this difficult time," said Durham Fire Chief Bruce Pagan.