Investigators in India are studying the black boxes of a Boeing 787 Dreamliner after recovering them from the aircraft wreckage to ascertain the cause of last week’s plane crash that left at least 270 people dead.

Multiple Indian agencies, including the National Security Guard (NSG), National Disaster Response Force (NDRF), Indian Air Force, forensic teams, fire and rescue services are inspecting the wreckage of the London-bound Air India jet, which crashed into the rooftop of a doctors’ hostel in Ahmedabad. The area remains fully cordoned off.