Firefighters got the call at approximately 11:23 on Wednesday night. They arrived at the three-story dwelling on the 1100 block of South 19th Street in Point Breeze, about two minutes later.
What they saw was a corner house engulfed in flames and smoke, and a man at the rear window on the third floor. The man jumped before firefighters could reach him, falling onto the garage roof.
The 78-year-old victim was rushed to the hospital, but efforts to save his life failed.
Investigators do not know what caused the fire, but they say it started in the basement. Renovations to the basement, including cementing over the sidewalk entrance, made it very difficult for firefighters to reach the source of the blaze. They had to cut through bricks to get to the fire.
It took an hour and a half to place the fire under control.
The house, which has a dentist's office on the first floor, is gutted.
The building had working smoke alarms. Firefighters heard them when they arrived.
One firefighter suffered smoke inhalation. He is expected to recover.
The elderly man's name has not yet been released.