Efforts are underway to reconstruct the sequence of events leading to the Air India plane crash this month that killed 260 people, and identify contributing factors, India’s civil aviation ministry said on Thursday.

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 ground in the world’s worst aviation disaster in a decade.

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.

They were transported to national capital Delhi on Tuesday, where a team led by India’s Aircraft Accident Investigation Bureau began extracting their data, the ministry said in a statement.

“The Crash Protection Module (CPM) from the front black box was safely retrieved, and […] the memory module was successfully accessed and its data downloaded […] the analysis of CVR and FDR data is underway,” it said.

The CPM is the core part of a black box that houses and protects data recorded during a crash.

India said last week that it was yet to decide where the black boxes would be analysed. The data retrieved from them could provide critical clues into the aircraft’s performance and any conversations between the pilots preceding the crash.

The air disaster has also brought renewed attention to violations of norms by airlines in the country.

India’s aviation regulator said on Tuesday that multiple instances of aircraft defects reappearing were found at the Mumbai and Delhi airports — two of India’s busiest.

Reuters has reported that warnings were given by India’s aviation regulator to Air India, which has come under increased scrutiny since the crash, including for permitting some aircraft to fly despite emergency equipment checks being overdue.

The airline has also been warned for violations related to pilot duty scheduling and oversight.

Air India has said it had implemented the authority’s directions and was committed to ensuring adherence to safety protocols.

It also said it was accelerating verification of maintenance records and would complete the process in the coming days.