Lorielle Russell, 18, and Jack Thatcher, 18, died after falling from Mount Beerwah in a tragic hiking incident. Image: Supplied

Lorielle Russell, 18, and Jack Thatcher, 18, died after falling from Mount Beerwah in a tragic hiking incident. Image: Supplied

A Queensland teenager is mourning the loss of her twin sister and boyfriend after they were killed in a tragic hiking incident at Mount Beerwah.

Lorielle Russell, 18, and Jack Thatcher, 18, died after they fell up to 100m during a descent on the slippery summit following rain on March 15.

Ms Russell died at the scene, while Mr Thatcher was flown to the Sunshine Coast University Hospital in a critical condition.

He was on life support until he died three days later.

Four other hikers needed help but were able to make their way safely from the mountain and did not require medical treatment.

Lorielle Russell, 18, and Jack Thatcher, 18, died after they fell up to 100m during a descent on Mount Beerwah following rain. Four other hikers needed help but were able to make their way safely from the mountain and did not require medical treatment. Picture 9News

Lorielle Russell, 18, and Jack Thatcher, 18, died after they fell up to 100m during a descent on Mount Beerwah following rain. Four other hikers needed help but were able to make their way safely from the mountain and did not require medical treatment. Picture 9News

Funerals for both 18-year-olds have been held in Brisbane this week.

Mourners gathered to farewell Ms Russell at Our Lady of Graces Catholic Church in Carina on Friday.

Her twin sister Arabella Russell was supported by family, friends, and classmates from San Sisto College, the Courier Mail reported.

The school paid tribute to Ms Russell in a Facebook post on Friday that was flooded with comments from people who remembered the young woman as an adventurous person full of life, and offered words of support for her family.

Brisbane teen Arabella Russell, 18, has farewelled her twin sister, Lorielle Russell, 18, as she prepares to say goodbye to her boyfriend after they fell from Mount Beerwah. Picture: GoFundMe

Brisbane teen Arabella Russell, 18, has farewelled her twin sister, Lorielle Russell, 18, as she prepares to say goodbye to her boyfriend after they fell from Mount Beerwah. Picture: GoFundMe

“Am heartbroken for the Russell family but so full of admiration for your strength and courage during today’s service for Lorielle,” a person commented.

“I hope it is some small comfort to you all to know that you have the full support and prayers of the SSC community (past and present), behind you all.”

“What a beautiful young adventurous woman. I am so sorry,” another person said.

Friends and family of the teens have gathered again to farewell Mr Thatcher at a service being held at Iona College in Brisbane on Saturday.

Jack Thatcher has been farewelled at Iona College in Brisbane. Picture: GoFundMe

Jack Thatcher has been farewelled at Iona College in Brisbane. Picture: GoFundMe

On an online fundraiser for Mr Thatcher’s family, organised by Ryan Orbell, he was described as an “adventurous spirit”.

“Jack was … simply enjoying his life in the great outdoors with his friends,” Mr Orbell wrote.

“If you can please help this beautiful family with any amount of contribution, it will help to ease some of the extra burden on the family during this terrible and horrific time.

“All funds raised will be provided to the family of Jack Thatcher to assist with all of their seen and unseen expenses as required.”