American Idol alum Doug Kiker has passed away at the age of 32 on Monday, but a cause of death has yet to be revealed, TMZ reported on Thursday.

The singer – who was also known as ‘The Singing Garbage Man’ – previously appeared on the competition show during its 18th season and auditioned with Rascal Flatts’ Bless the Broken Road.

His ex-fiancée Valerie Cook confirmed his shock death, as well as family members including his sister Angela and brother William.

In a post on social media, Angela heartbreakingly revealed that Kiker’s passing was ‘unexpected’ and his loved ones were ‘completely unprepared.’