Investigators have retrieved the flight data recorder from the wreckage of a US-Bangla Airlines passenger plane that crashed, killing at least 49 people on board, as it attempted to land at Kathmandu, a senior airport official in Nepal’s capital said on Tuesday.

The airline and airport authorities have blamed each other in the aftermath of Monday’s aviation disaster, the worst suffered by the Himalayan country since a 1992 Pakistan International Airlines (PIA) crash that claimed 167 lives.

“The flight data recorder has been recovered we have kept it safely,” said Raj Kumar Chettri, the airport’s general manager, adding that an investigation into the cause the crash had begun.

The US-Bangla plane involved in the crash was a Bombardier Q400 series aircraft. It was carrying 71 people and was en route from Dhaka.

Canadian plane maker Bombardier said it is sending an air safety investigator to the site, as well as a field service representative.