Answer by taking a quote from the following article:

Rory Storm (7 January 1938 - 28 September 1972) was an English musician and vocalist. Born Alan Ernest Caldwell in Liverpool, Storm was the singer and leader of Rory Storm and the Hurricanes, a Liverpudlian band who were contemporaries of the Beatles in the late 1950s and early 1960s. Ringo Starr was the drummer for the Hurricanes before joining the Beatles in August 1962, replacing original drummer Pete Best.

In 1967, at the age of 26, O'Brien collapsed on stage during a performance, and later died due to complications after an appendicitis operation. Storm disbanded the Hurricanes and became a disc jockey, working at the Silver Blades Ice Rink in Liverpool, in Benidorm (he was also a water-skiing instructor there) in Jersey and Amsterdam. When Storm's father died, he returned from Amsterdam to Liverpool to be with his mother. He developed a chest infection and could not sleep properly, so he took sleeping pills. On 28 September 1972, Storm and his mother were both found dead, at Stormsville. The post mortem revealed that Storm had alcohol and sleeping pills in his blood (as had his mother) but not enough to cause his death, which was ruled accidental. Although it could not be proven, it is thought that his mother had committed suicide after finding Storm's body.  The funeral for Storm and his mother was at Oakvale Congregational Church, Broadgreen, on 19 October 1972. Mourners sang Storm's favourite song, "You'll Never Walk Alone". The two coffins were carried from the hearse to the cremation (at Anfield Crematorium) by former band members. Storm's remains were scattered on section 23 at Anfield Crematorium's Gardens of Remembrance. When Starr was asked why he did not attend, he said, "I wasn't there when he was born either." Although Starr had often offered to arrange for Storm to record whenever he wanted to, Storm was not interested in finding new or original material. His sister said: "He [Storm] was happy to be the King of Liverpool--he was never keen on touring, he didn't want to give up running for the Pembroke Harriers ... and he'd never miss a Liverpool football match!"  Billy Fury, who Storm had met at the Wyvern Club auditions, later played the part of a fictional singer called Stormy Tempest (based on Storm), in the film That'll Be the Day (1973), which also starred Starr. In 1987, a musical was staged in Liverpool about Storm and the Hurricanes called A Need For Heroes.  After spending several years in the Merseyside Ambulance Service, Johnny "Guitar" Byrne died in Liverpool on 18 August 1999.

How did he die?
He developed a chest infection and could not sleep properly, so he took sleeping pills. On 28 September 1972, Storm and his mother were both found dead,