Authorities have suspended the operating licence of charter airline LaMia Bolivia after 75 people, including players from Brazil’s Chapecoense football club, were killed when one of its aircraft crashed in Colombia on Monday night. The management of the Bolivian aviation authority was also replaced to ensure a transparent investigation, reported The Guardian.

The aircraft, BAe 146, crashed in the hills outside the city of Medellin, because its fuel reserves were low, investigators said. A recording revealed that Bolivian pilot Miguel Quiroga had informed the control tower at Medellin airport that the plane was “in total failure, total electrical failure, without fuel”. He had requested permission for an emergency landing. The air traffic controllers at Medellin had reportedly asked the pilot to wait while another flight made an urgent landing. The audio clip was accessed by Colombian media. Now, the aircraft’s black boxes, which record flight details, will be sent to United Kingdom, where investigators will download the information.

According to international flight regulations, aircraft need to have enough reserve fuel to fly for 30 minutes after reaching their destinations. “In this case, sadly, the aircraft did not have enough fuel to meet the regulations for contingency,” Freddy Bonilla, secretary of airline security at Colombia’s aviation authority, told The Guardian.

There are also reports that the pilot was warned about low fuel before take-off, according to BBC. An official of the Bolivian airport authority at the Santa Cruz airport, from where it took off, had raised concerns that the plane’s fuel load was just enough for the flight duration. However, the airline’s clerk allegedly told the official that the pilot was confident, BBC reported, quoting a local Brazilian newspaper. However, Bolivian officials are yet to comment on this.

Meanwhile, air traffic controller Yaneth Molina, who had received the final call from the pilot, said that she had received death threats after the crash. “I did all that was humanly possible and technically necessary to preserve the lives of the passengers, but unfortunately my efforts were not enough,” Molina said in a letter.

Of the 81 people on board, only six survived the crash – three Chapecoense team members, two Bolivian crew members and a journalist. While goalkeeper Jackson Follmann’s right leg has been amputated, defender Helio Neto is in intensive care with severe trauma to his skull, thorax and lungs, and defender Alan Ruschel underwent a spinal surgery. The Bolivian crew members, Ximena Suarez and Erwin Tumiri, got bruises while journalist Rafael Valmorbida has multiple rib fractures that partly collapsed a lung, according to The Guardian.