JAKARTA, Indonesia (AP) — Divers on Thursday recovered a flight data recorder from the crashed Lion Air jet on the seafloor, a crucial development in the investigation into what caused the 2-month-old plane to plunge into Indonesian seas earlier this week, killing all 189 people on board. CNN Indonesia showed images of divers bringing the device, commonly known as a “black box,” on board one of the rescue ships in the sea close to Jakarta Thursday, four days after the Boeing 737 MAX 8 jet disappeared off radar during a routine short-haul flight. It was the worst airline disaster in Indonesia in more than two decades and renewed concerns about safety in its fast-growing aviation industry, which was recently removed from European Union and U.S. blacklists. WATCH: Indonesia airliner crashes minutes after takeoff, killing all 189 on board

The device recovered by divers is the flight data recorder and the search for the cockpit voice recorder continues, said Bambang Irawan, an investigator with the National Transport Safety Commission. “We cannot say how long it takes to process data in a black box, but of course we will try as soon as possible.”

The flight data recorder was recovered from a depth of 30 metres, about 500 metres northwest from where the plane lost contact, said search and rescue agency head Muhammad Syaugi. The flight data recorder, or FDR, is expected to provide investigators with detailed information about the flight such as altitude, airspeed and heading. READ MORE: Pilot asked to return Indonesian plane to base before it plunged into sea with 189 people on board

The Lion Air crash is the worst airline disaster in Indonesia since 1997, when 234 people died on a Garuda flight near Medan.
Indonesian divers retrieve the flight data recorder from the ocean near Karawang, Indonesia, where the plane had crashed three days prior.