Kuala Lumpur , Malaysia ( CNN ) -- The families of those on board Malaysia Airlines Flight 370 have been waiting for answers for 20 days . The loved ones of those who were passengers on Malaysia Airlines 653 have been waiting for 37 years . Flight 653 was hijacked in 1977 en route from the northern Malaysian city of Penang to Kuala Lumpur , the country 's capital . The airliner -- a Boeing 737-200 -- crashed into a mangrove swamp as it descended , killing all 100 on board . Before Flight 370 , it was the deadliest incident in Malaysian aviation history . Is it or is n't it ? Latest images give analysts hope . `` Thirty-seven years down the line , we still do n't really know the truth , '' said Ruth Parr , who was 19 when her father , Thomas , died in the crash . The hijacker or hijackers of MH653 have never been identified , despite cockpit voice recordings that captured everything from the breach of the cockpit , to the sound of gunshots that killed both pilots . According to the Malaysian Civil Aviation Department 's report into the crash , the aircraft was hijacked as it approached Kuala Lumpur . Amid confusion over whether it was to land there or not , it proceeded towards neighboring Singapore . As it descended , the crew was shot and the aircraft `` carried out some unusual pitch up and pitch down terminal maneuvers before finally impacting into swampy ground at some 450 knots . '' The report concluded that the crash was caused by the crew being fatally incapacitated , leaving the aircraft `` professionally uncontrolled . '' However , some eye witnesses at the time reported seeing the aircraft in flames before it hit the ground , while others reported hearing an explosion before impact -- though investigators could not find evidence to support these reports . Defining event . For other family members of MH653 victims reached by CNN , the recent disappearance of MH370 brought back memories of that traumatic time . Over the years , they have learned to cope with their grief , but the 1977 crash will always be a defining event in their lives . 'Unspeakable challenge ' for relatives . `` You have to carry that with you all the time , '' said Tom Sherrington , whose father , Richard , was also on MH653 . He believes talking openly about their memories of his father , whom he described as a `` fun guy '' and `` big adventurer , '' helped his family to cope . He also said visits to the memorial , built near the crash site in the Malaysian coastal town of Tanjung Kupang , have given his family a tangible place to reflect on their loss . As for the families of those on board MH370 , Sherrington said they should focus on remembering their loved ones and try not to fixate on assigning blame . `` The one thing I would say is not for them to get too obsessed with the detail and the recriminations and all that , '' he said . Sherrington added that he hopes the families will stick together and find comfort in each other . China treads carefully amid anger and grief of relatives . 'You can never forget the date ' Both Parr and Sherrington warn that everyone processes their grief in different ways and there is no shortcut . It gets a little easier over time but you can never forget the date , '' Parr said . `` You will forever think you see that person out and about , a glance in the car 's rearview mirror or crossing the road . It could be anywhere , a voice that sounds like him will have you spinning around only to find it 's someone else . '' Hopes dashed as orange objects turn out to be fishing equipment . Get up to speed on the latest developments . A flight attendant 's husband wants to give children answers , but has none .
Malaysia Airlines Flight 653 crashed after being hijacked in 1977 . Report into crash said the pilots were shot dead and plane slammed into the ground . Relatives of the passengers say current crisis with MH370 brings pain flooding back . One advised families to remember loved ones and not fixate on assigning blame .