SOUTH MIAMI, Fla. -- Firefighters searching through a building that caught fire Wednesday morning found a body inside one of the apartments.

Miami-Dade firefighters started battling the two-alarm blaze at the building, located at 7430 SW 59th Court in South Miami, at about 7 a.m.

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The fire started in an apartment on the second floor, then spread to the apartment next door, investigators said.

Residents of the building went door to door to warn their neighbors, but no one could get the attention of the woman who lived in the unit where the fire was at its worst.

"I smelled smoke. I knocked on the door and went upstairs and started knocking on everybody's door," said neighbor Jose Paez. "I didn't know if she was there or not. I couldn't tell."

"Before we even called the fire department, we were knocking on all the doors. All the neighbors were really good about it," said another neighbor. "But on that particular door, the door was just way too hot."

It was too hot even for Miami-Dade Fire Rescue.

"The firefighters, when they encountered the apartment of origin, they could not perform a search because the whole apartment was covered in flames," said Lt. Arnold Piedrahita of Miami-Dade Fire Rescue. "So the search had to be performed after the fire was extinguished."

In the apartment, firefighters found a body burned beyond recognition.

Firefighters rescued two people who were trapped on a balcony, according to Miami-Dade Fire Rescue.

The three-story building was evacuated, and no other injuries were reported.

Felix Machado, the building manager at the complex, lives across the unit from where the fire started.

"She's a very quiet person," Machado said. "She's a nurse, used to come in and out. Nobody knew she was a chain smoker."

Building inspectors called the building uninhabitable, and the American Red Cross is helping the residents of the 29 units to find another place to stay.

Miami-Dade Fire Rescue continues to investigate the cause of the fire.