Investigators have downloaded flight recorder data from an Air India crash this month that killed 260 people, India’s civil aviation ministry said on Thursday, a long-awaited step towards understanding the world’s worst aviation disaster in a decade.

The London-bound Boeing 787 Dreamliner crashed moments after takeoff from India’s Ahmedabad city on June 12, killing 241 of the 242 people on board and the rest on the ground.

The black boxes of the plane – the cockpit voice recorder (CVR) and flight data recorder (FDR) – were recovered in the days that followed, one from the rooftop of a building at the crash site on June 13, and the other from the debris on June 16.

The ministry said data from the front recorder was accessed on Wednesday by a team led by India’s Aircraft Accident Investigation Bureau (AAIB), with the US National Transportation Safety Board.

“These efforts aim to reconstruct the sequence of events leading to the accident and identify contributing factors to enhance aviation safety and prevent future occurrences,” the ministry said in a statement.