Grieving mum recalls final conversation with her teenage son Levi-Jackson Furnivall before he was killed in horror highway crash

A distraught mother has recalled her teenage son final words to her before he was killed when the car he was travelling in slammed into a tree.

Levi-Jackson Furnivall, 17, was in the backseat of a red Mitsubishi Magna sedan when the vehicle veered off the Tonkin Highway in Martin in Perth 's south-east at about 1.40am last Thursday morning.

The vehicle rolled before hitting a tree about 1.40am, trapping the teenager inside who couldn't be revived.

Nine hours earlier, the last thing Levi-Jackson told his mum Atariki Simon-Whararapa was that he and a few friends were heading out to check on a mate.

While she's grateful the driver, 19, and other passenger, 18, escaped with minor injuries, she's struggling with the loss of her son.

'I know he was with his mates . . . he hadn't heard from one of his best friends all day, and they wanted to go check on him,' she told The West Australian .

'The crash was at 1am, but he left at five in the afternoon, and he said he wasn't going to be long.'

Ms Simon-Whararapa recalled how he hadn't heard from her son and 'couldn't get a hold of him' - so she texted one of his friends, who also didn't answer.

She had no idea what had happened to Levi-Jackson until she was in the shower later that morning.

The teen's mother said her and her family 'are just broken' and can't believe how suddenly he had been taken from them.

Ms Simon-Whararapa recalled how she'd been helping her son organise his tax file number ahead of starting a mechanics apprenticeship hours earlier.

The family's beloved son and brother had been at the house with them before the accident, 'laughing with us and joking with his sister'.

Levi-Jackson had a 13-year-old brother and seven-year-old sister and was described as someone who always had a lot of energy.

The forgiving mother said even though she was 'hurting' she had no anger towards the young driver.

The devastated mother revealed that none of her son's friends have been in touch since the tragedy.

She wanted them to know that they shouldn't be 'scared' of her, saying she is 'angry at the situation' but not them.

Ms Simon-Whararapa wanted people to celebrate her beloved son's life.

There was an outpouring of grief online for the popular 17-year-old.

'Gone way too soon my brother, I never imagined losing a friend, it was just something I didn't think would happen,' one friend wrote.

Parts of Tonkin Highway remained closed on Thursday morning as major crash officers examined the crash scene,

Anyone with dashcam footage or who had witnessed the crash to contact WA Police.