The Regional Service for the Investigation and Prevention of Aeronautical Accidents in Brazil had their hands full with the mystery of why a rescue helicopter literally shook itself to pieces on wednesday of last week.

The chopper carried four passengers who all sustained injuries during the malfunction. Presently, official believe that the rotor of the craft failed to disengaged while on the ground creating a mechanical phenomenon known as ‘ground resonance’.

Little else has been reported about the accident. No word on the severity of the injuries of those aboard the craft or where the it was returning from. Fire and rescue workers witnessed the mishap from close by.

The Telegraph provides this amateur video of the event taken by the Para Fire Department: