One year after a Lion Air plane crash that killed 189, relatives and friends of victims held prayer vigils and cast flower petals into the Java Sea at the site where the budget carrier's Boeing 737 MAX jet went down beneath the waves.

The almost new Boeing Co aircraft had been flying from the Indonesian capital of Jakarta to the town of Pangkal Pinang, on the Bangka-Belitung islands off Sumatra, when it crashed within minutes of take-off.

‘This cannot be forgotten because it was such a tragic and unbelievable event,’ said Epi Samsul Komar, whose 24-year-old son, Muhammad Rafi Andrian, was on the doomed flight, JT610.

‘Hopefully this flower-scattering ceremony can heal our longing for our child,’ Komar told Reuters.

He was among the families of victims who went by boat to the crash site off the West Java district of Karawang to throw petals into the sea, a tribute they also performed last Nov. 8.

Tuesday's event came days after Indonesian investigators issued their final report on the disaster, setting out Boeing's failure to identify risks in the design of cockpit software and recommending better training for Lion Air's pilots.

The fatal crash, followed within five months by another at Ethiopian Airlines, led to a global grounding of the Boeing 737 MAX and a crisis for the world's biggest planemaker.

Stan Deal, newly appointed president and chief executive of Boeing Commercial Airplanes, attended the ceremony in Jakarta, at which he told Reuters he was there to pay his respects.

Deal's predecessor, Kevin McAllister, was ousted by Boeing last week, the first high-level departure since the two crashes.

In the town of Pangkal Pinang, tax office employees held special prayers for seven colleagues killed in the crash, the office head, Krisna Wiryawan, said.

A tribute video featured photographs of the victims in happier times.

‘When the loved ones are gone, only memories remain,’ read a message near the end of the video. ‘These memories will remain in our hearts.’

Indonesian regulators criticised the design of the 737 MAX's anti-stall system, known as MCAS, which automatically pushed the plane's nose down, leaving pilots fighting for control.

Investigators attributed the Lion Air crash to a number of factors, including design flaws and inadequate regulatory oversight, as well as errors by Lion Air pilots and engineers.

Lion Air was ‘always improving upon pilot skills and maintenance because it's a never ending job in the airline industry,’ Chief Executive Edward Sirait told reporters at Tuesday's event.

Boeing ran a statement in Indonesian newspapers in which its president and chief executive, Dennis Muilenburg, said, ‘We are deeply sorry and grieve for the loss of life.’

‘May God rest their souls in peace, provide strength to their families, and keep their memories alive,’ he said.

Muilenburg also visited the Indonesian embassy in Washington to offer condolences a day before he is due to testify before the US senate on Tuesday.

Indonesian Finance Minister Sri Mulyani Indrawati said she hoped victims' relatives would receive proper compensation.

Boeing settled first claims with family members' representatives in September. Three people familiar with the matter said family members are set to receive at least $1.2 million each.

That figure is compensation for a single victim without any dependents, the sources said, speaking on condition of anonymity because negotiations were confidential.


Related Story