NEW DELHI (AP) — Investigators have begun analyzing data extracted from the black boxes of the ill-fated Air India Boeing 787 Dreamliner that crashed about two weeks ago, killing at least 270 people, India’s civil aviation ministry said on Thursday.

The data is crucial as it will help shed light on the cause of the country’s worst aviation disaster in recent memory.

A team led by India’s Aircraft Accident Investigation Bureau, or AAIB, has started looking at the data with support from the U.S. National Transport Safety Board, the ministry said in a statement.

“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.

Indian investigators recovered the black boxes from the wreckage site in the northwestern Indian city of Ahmedabad, a couple of days after the London-bound Air India flight 171 struck a residential area minutes after takeoff. The crash killed 241 people onboard and at least 29 on the ground. There was one survivor.

The so-called “black box” is one of the most important pieces of forensic evidence following a plane crash. There are typically two sturdy devices, the cockpit voice recorder and the flight data recorder. And they’re typically orange, not black.

Indian authorities flew the black boxes from Ahmedabad to the national capital in an Indian Air Force aircraft amid tight security early this week. The investigation could take weeks or months.

India set up a state-of-the-art laboratory in New Delhi in April to help AAIB repair damaged black boxes and retrieve data to enhance the accuracy of investigations.

A multidisciplinary team led by AAIB Chief GVG Yugandhar is probing the Air India crash with assistance from aviation and air traffic control specialists and experts from the National Transport Safety Board.

The Indian government has also set up a separate, high-level committee to examine the causes leading to the crash and formulate procedures to prevent and handle aircraft emergencies in the future. The committee is expected to file a preliminary report within three months.

Following the June 12 crash, Indian authorities had ordered deeper checks of Air India’s entire fleet of Boeing 787 Dreamliner to prevent future incidents.

Air India has 33 Dreamliner in its fleet. Inspection has been completed for at least 26 while four were undergoing long-term maintenance. The rest were expected to finish the safety checks soon.