The fire occurred at a home along the 200 block of East Elm Street at around 7:00 p.m.
"I looked down the street and I saw all these flames coming out of the end house," neighbor Eugene Horveath said.
So the neighbor called 911, panicking as heavy flames burst the home.
Fire officials say two people were in the end row-home where the fire started.
One of them was a 16-year-old boy trapped in the area of the bathroom on the second floor.
The fast moving flames spread to two other homes; a fourth home may have smoke damage.
Firefighters immediately began working to get to the teen, to no avail.
"We began a search and rescue immediately to try and get to the victim, the fire was just so intense and the smoke was so thick and toxic, it was really little chance for survival," Allentown Fire Department Chief Robert Scheirer said.
Red Cross officials responded to the scene. Authorities say 16 people have been displaced.
The identity of the victim has not been released.
The cause of the fire is being investigated.