The fire broke out around 10:45 p.m. along the 2600 block of Abington Road.
Sandy Ross ran outside from her home two doors away, called 911, and started recording the dramatic scene.
"I was upstairs in my office and I just heard what sounded like a loud bang or pop, almost sounded like metal on metal," Ross said.
Friends of the victim dropped him off just moments before Ross heard the bang and saw fire.
The friends reportedly tried to run in to save the victim; onlookers calling 911 heard the screams.
"She ran around back, she could hear him yelling for help, but it was too much, the flames were just too much," Ross said.
"Fire department responds, Talleyville responds, gets the fire under control and they find one person inside deceased," Michael Chionchio, Assistant Delaware State Fire Marshal, said.
The Delaware Office of the State Fire Marshal remained on the scene overnight and into the morning.
Fire crews also returned when flames flared up inside what was left of the gutted split level home.
"Right now we have a home that was destroyed by the fire. What we need to do is reconstruct the home and try to find out the origin of the fire and what caused the fire," Chionchio said.
Officials have not released information about the victim except that he is in his 50s.
Neighbors say he had difficulties walking and lived alone.
One of the residents on the block that was briefly displaced by this fire reported they felt chest pains and was taken to the hospital, but they are OK.
There were no reports of any injuries to firefighters.