A man trapped by a fast-moving fire in a Middlesex County apartment building dropped his young child into the waiting arms of police and firefighters, who then also caught the man.

Authorities say the fire at the South Ridge complex in South Brunswick was reported around 8:15 a.m. Monday. Emergency responders found flames shooting from the second and third floors of the rear of one of the buildings.

The man and his 3-year-old son were on a second-floor balcony when authorities told the dad to drop the boy.

Sgt. William Merkler, PFC Ryan Bartunek, Detective Sgt. John Penney and Fire Chief Chris Perez caught the child. The father soon followed.

Firefighters had entered the building to search for people but were forced out because of that heavy fire.

Both the father and son were treated for undisclosed minor injuries. Four other residents were treated for smoke inhalation

Authorities say that at least 50 people were displaced because of the fire. The American Red Cross is helping displaced families.

The cause of the fire remains under investigation.