Indian investigators have successfully retrieved data from the black boxes of a Boeing plane, after it crashed in one of the deadliest air disasters in decades, the government said Thursday.

All but one of the 242 people on board the Air India flight were killed on June 12 when the jet crashed in the western city of Ahmedabad, where at least 19 others were left dead.

Two weeks after the disaster, the civil aviation ministry said investigators have started “the data extraction process” from the plane’s cockpit voice and flight data recorders.

“The analysis… is underway. 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,” a ministry statement said.