• BREAKING NEWS ABC shows live and on-demand -- Download the WATCH ABC app!

Rescue helicopter in Brazil falls apart after landing

February 24, 2012 12:00:00 AM PST
Investigators in Brazil are trying to figure out why a rescue helicopter disintegrated shortly after landing.

Amateur video caught the aircraft as it came apart on the ground.

Four people were injured in the accident, which occurred in the northern state of Para on Wednesday.

Brazil's Regional Service for the Investigation and Prevention of Aeronautical Accidents believe the helicopter experienced a condition called ground resonance, which occurs when the aircraft's rotor is turning while the helicopter is on the ground.