A child died and five other people were injured after an overnight fire tore through an apartment building in Perth Amboy around 2:45 a.m., leaving about 26 residents from six units awake and scrambling for safety.

Working smoke detectors gave residents precious seconds to react, and some were able to get out before the flames spread. Police and fire officials said the injuries included two burn victims who were flown to the hospital, two first responders with minor injuries and another resident with a minor injury.

The fire chief said there were heavy flames and the side of the apartment took the worst damage. Officials also said the blaze appeared to have started on the second floor, and fire crews remained on Chauncey Street investigating the exact cause as morning set in.

Johanel Fernandez said he helped a man with burns get out of the building. He said the only thing on his mind was saving the man’s life, a split-second decision that underscored how quickly the fire turned dangerous even after the alarms sounded.

Helmin Caba said the loss was devastating for the family and the wider community, and asked residents to keep the family in their thoughts and respect their privacy. He said the city was grateful to the police officers, firefighters, EMS personnel and mutual aid partners who responded under difficult conditions, but the unanswered question remains what sparked the fire on the second floor and how a building with working smoke detectors still ended with a child dead and five people hurt.