An explosion in a Brownsville apartment complex injured four people and caused major damage to the building Thursday.

Tenants at 7 Hegeman Ave. blamed the incident on a so-called bug bomb, which is used to kill insect infestations. The pesticide exploded with enough force to blow out windows.

Authorities say two of the victims suffered serious injuries. The other two sustained minor ones. All four were taken to Brookdale Hospital.

Andre Chandler, who lives on the 16th floor, says he felt the blast shake the building.

"I've been here over 20 years, but I'm kind of concerned," he says. "Living in a high-rise apartment building -- what happens if there's a fire?"

Fire officials say they're not sure what caused the chemical to ignite.