MIAMI (WSVN) - Miami Fire Rescue said the structure fire that sent two firefighters to the hospital appears to have been set intentionally.

“We received a call for a three-story unoccupied structure that’s under renovation,” said City of Miami Fire Rescue Lt. Pete Sanchez.

The fire was sparked at a building under renovation around 6:30p.m. Monday near the area of Northwest First Avenue and 14th Street in Overtown.

“When our units arrived, they found heavy smoke coming from all three floors,” said Lt. Sanchez.

Firefighters battled the blaze for two hours and as they did officials said one of them fell through the floor.

“We had a firefighter who was working on the second floor who fell through the first floor,” said Lt. Sanchez. “Luckily he landed. He was safe. He made his way out. He was evaluated immediately, but he was taken to the hospital just for precaution.”

A second firefighter suffered second-degree burns to their ear and forearm.

Although the building appeared to be vacant at the time of the fire, crews still went inside and conducted a thorough search.

“That’s the danger of firefighting and risking and going inside and making sure it was safe and no one was inside at the time of the fire,” said Lt. Sanchez.

Photos of the aftermath showed the beams and of the celling covered in soot.

Both firefighters are expected to be OK but the question is no longer ‘how’ the fire started, but by who.

State Fire Marshals and Miami Police detectives are now the lead agencies on the investigation.