BROOKLYN, N.Y. - Fire officials are investigating after a fire tore through three homes in Brooklyn early Thursday morning. According to sources with knowledge of the case, the incident is now being considered an act of arson.

Investigators say at least 12 people were hurt, including eight adults and one child. Three firefighters were also hurt, but most of the injuries are minor and were caused by smoke inhalation. 

Sources tell NY1, 41-year-old Pennsylvania native Matthew Karelefsky is believed to be the man behind the fire, and that he sustained burns while leaving the scene. He is known to authorities and has had previous run-ins with the law.

Sources also tell NY1 that Karelefsky was arrested back in 2018 after he threatened a Rabbi via email, who the suspect claims molested him as a child. According to sources, he even has a tattoo calling out that rabbi on his right arm.

The FDNY said the four-alarm fire began around 4 a.m. inside 1488 East 17th Street in Midwood, before spreading to two neighboring homes.

When firefighters arrived just after 4 a.m., the homes were engulfed in flames and thick smoke filled the area.

All the homes suffered extensive damage. 

Of all the civilians and firefighter injured, a 6-week-old baby was the most seriously injured. NY1 caught up with the child's grandmother, who was horrified someone did this intentionally.

"Doesn't he think about anyone else besides the person who wants to take revenge on?” said Terry Herzog. “It is just absolutely terrible that someone would do something like that. There are so many people affected by it who are now displaced and don't have anything, completely gone. Completely.”

The fire was declared contained just after 7 a.m.

The Red Cross is assisting the families displaced by the blaze.