HE would "do anything for anyone", his dad says, and adored his two young daughters, but grief over the loss of his brother Bailey was brutal to Mitchell Sibraa.

On Saturday the 23-year-old took his own life.

His parents Amanda and Steven Sibraa discovered their eldest son's body in their Sunshine Coast home, in front of Bailey's photo memorial and urn.

Bailey was killed at Buddina last January, at age 19, when a ute he and two friends were in crashed into a tree.

Amanda and Steve had returned from Brisbane on Saturday for a celebratory family lunch, Steve said. It was their daughter Soraya's 19th birthday.

"Mitch was looking forward to it," Steve said.

He spoke with difficulty through the grief and tears, his words catching on each other.

Soraya was "shattered" and Mitchell's mum Amanda "absolutely devastated'.

"Amanda is just...it's one thing to have one child taken from you but to have two?" Steve said.

"Two beautiful boys and...it's just so unfair. He was everyone's mate."

Since Bailey's death everyone in the family had struggled with mental health, Steve said.

Mitch suffered the most, and couldn't talk about it much.

"We often tried to talk to him," Steve said.

"He struggled with admitting that he was feeling that way.

"He'd just get all defensive and push back a little bit, say that he was okay, everything was fine."

Steve said events like Bailey's death have a "snowball effect", damaging the lives of everyone who loved him.

"Mitchell just couldn't cope," he said.

"He loved Bailey like no-one else. His best mate and he just wanted to be with him at the end of the day."

Mitch had been diagnosed with depression and had been seeing psychologists and psychiatrists.

"He didn't really take any time off after Bailey, he just went right back to work," Steve said.

"He just pushed through it all and we thought he was okay."

Mitch left behind his partner Tahnii Cunning, two daughters Indii, 2, and Amity, 10 months.

He had spent his last day on Friday with his daughters, drawing rockets with wings "so they could fly".

"Little Indii is just absolutely obsessed with him. Her Daddy," Steve said.

An airconditioning refrigeration mechanic, Mitch had planned to start his own business and had "so many plans" Steve said.

Mitch had "picked up where Bailey left off", making sure his parents had help around the house and never leaving them wanting for anything, Steve said.

Amanda and Steve had recently started to "live life the way Bailey would have wanted us to" and felt life was improving after his loss.

"...you know, suicide doesn't necessarily take the pain away, it just passes it on to someone else," Steve said.

"This has just sort of put us back into a big hole."

Asked what he would remember Mitch for, Steve said: "He's just so caring and loveable and... he had the time in the world for everybody," he said.

"He's smart, caring, loveable, outgoing and very much about family - all about family, and friends."

To give to Mitch's partner Tahnii and their two children visit www.gofundme.com/mummy-in-need

Mental health help is available:

• Lifeline 13 11 14
• Suicide Call Back Service 1300 659 467
• Beyondblue Support Service 1300 22 44 36
• Kids Helpline 1800 551 800