HOUSTON -- The most recent fire in the Houston's Heights neighborhood does not appear to have been intentionally set, but residents are still worried, KPRC Local 2 reported.

The fire started around 3:15 a.m. Tuesday at a home on Nashua Street near West 15th Street. The family of three inside managed to escape without injury.

"The guy who actually lives in that house, he's on crutches," neighbor Mary Arnold said. "Hopefully he's OK more than anything."

Preliminary reports are that the fire may have been caused by a faulty air conditioning unit.

Families in the neighborhood are still concerned. There have been at least 17 suspicious fires in the neighborhood since August.

"You're on edge and don't want to put your guard down until they catch whoever is doing it," Arnold said.

An arson team roped off about a three-block radius so investigators and arson dogs could search the area as a precaution.

Some residents said the investigation has been bothersome.

"They make me mad because they come knocking on my door asking me what I been doing this morning," Fernando Howard said.

Howard said he's lived in the area for a couple of years, but his family is leaving.

"I'm ready to move," Howard said. "Moving out this weekend and moving across the freeway."

A man arrested earlier this month in connection with one of the 17 fires is still in jail.