US Ice Bucket Challenge activist dies aged 37

Patrick Quinn, from New York state, was diagnosed with ALS, also known as Lou Gehrig's disease, in 2013.

"It is with great sadness that we must share the passing of Patrick early this morning," his team wrote in a post in Quinn's ALS advocacy Facebook group, "Quinn for the Win."

"We will always remember him for his inspiration and courage in his tireless fight against ALS."

Quinn did not start the Ice Bucket Challenge, which took social media by storm in 2014, but he and his family and friends helped it become a global phenomenon.

Millions took up the challenge, which involved dousing themselves with a bucket of ice cold water and posting the video online, before making a donation to medical research and daring others to do the same.

A galaxy of celebrities, high-profile personalities and entire sports teams took part in the challenge, including Tom Cruise, Steven Spielberg, Bill Gates and even former US president George W. Bush.

The campaign has reportedly raised $220 million to fund research into ALS, whose sufferers' bodies slowly shut down as their nervous systems degenerate.

In a statement, the ALS Association thanked Quinn for co-founding the Ice Bucket Challenge and mourned his death.

"Pat fought ALS with positivity and bravery and inspired all around him. Those of us who knew him are devastated but grateful for all he did to advance the fight against ALS."

The condition, officially known as amyotrophic lateral sclerosis, is also known as Lou Gehrig's disease after a baseball player who died of it in 1941.

Pete Frates, a former US college baseball player diagnosed with ALS who also inspired the ice bucket challenge, died last year at the age of 34.