Five years ago, Danica Week's husband simply vanished. She's still searching for answers.

In the early hours of March 8, 2014, the Malaysian Airlines flight MH370 disappeared. What happened to the plane is still a mystery.

Carrying 239 passengers, plus crew, its vanishing has caused heartbreak for families worldwide. Despite an international search effort, the cause of its demise has never been determined and none of the victims have ever been found.

On that flight was Paul Weeks. Paul was married to Danica and they had two young boys together, Jack and Lincoln.

As the five year anniversary approaches of her husband’s disappearance, Danica is still searching for answers.

Tonight on 60 Minutes, Danica talks to reporter Sarah Abo about why it’s necessary that investigators don’t give up on answering ‘why’.

“This isn’t just about 239 people on a Boeing 777, this is about eight million people every day that get on a flight: wives, husbands, family members that get on a plane,” Danica says.

Danica’s determination will tonight lead her to talk to Malaysian Prime Minister Mahathir bin Mohamad – astonishingly, the first time he has ever spoken to a relative of a victim of the disappearance.

Danica is hoping her personal plea to the Prime Minister will reopen the search for the missing plane.

Talking to New Zealand Herald, Danica shared why she refuses to stop searching.

"I'm not giving up... my biggest fear is if I don't find out what's happened. That's my burden, but it shouldn't be [my sons']. They're smart boys, just like their father, and I know they'll want to find out what happened.

"We all need closure."

Danica further shared how she deals with the grief, telling the publication, "With the boys, and for the boys".

"They keep me going every day ... otherwise I wouldn't be here. I just wouldn't be here under this pressure and this pain."

As for what happened to the plane, Danica is of the theory that a malfunction was the cause. But others are convinced the vanishing was mass murder-suicide on the pilot's behalf - a theory explored on tonight's episode of 60 Minutes.

The Channel 9 show will also interview Peter Chong tonight, a close friend of MH370’s commanding pilot, Captain Zaharie Ahmad Shah.

"Anybody that knows captain would immediately tell you that he's not this kind of person that would do such a thing," says Chong.

Danica told The Herald: "I never believe in crucifying someone without facts and I don't think that's fair on the pilot's family ... to throw him under the bus, for this is unfathomable".

60 Minutes has also been granted access to "the secret vault", which houses a piece of wreckage from the plane, found in the Western Indian Ocean.

The motive for the tragedy of MH370 may be buried with the plane, or it could lie in the fragments of debris that remain. And with that small piece of hope, Danica won't stop searching and asking 'why'.

She has confidence in knowing, as she said to NZ Herald, "He hasn't been taken by aliens. He has to be somewhere".

60 Minutes airs tonight at 8.30pm on Channel Nine.