The star was best known for collaborating with The Flaming Lips, who have confirmed her passing.
During their show in Portland on Monday night (07.10.24), singer Wayne Coyne said on stage that Nell was "killed in a car accident".
He told the crowd: "We have a very sad announcement to make tonight. "We have a Canadian friend, her name is Nell. We recorded an amazing album with her three years ago, an album full of songs by Nick Cave. We have some very sad messages today - she was killed in a car accident last night (06.10.24).
"We are reminded once again of the power of music and how encouraging it can be to be around people that you love."
Simon Raymonde, who played bass and keyboard for Scottish band Cocteau Twins, paid tribute to the late star and revealed she was preparing to release her first solo album.
He wrote on Instagram: "We are all shocked and devastated to hear of the sudden and tragic passing of our artist and dear friend Nell Smith, over the weekend in British Columbia. Nell was just 17 and was preparing for the release of her first solo record in early 2025 on Bella Union, made in Brighton with Penelope Isles' Jack and Lily Wolter. Her first release was an album of covers of Nick Cave songs recorded with fellow Bella Union artistes The Flaming Lips back in 2021 entitled, "Where The Viaduct Looms."
"While we all try and come to terms with the awful news, and out of respect to Nell's grieving family, we are unable to make any further comments at this time. The Bella Union Family."
Nell's family wrote in a statement via Instagram: "It pains us so much to say that our feisty, talented, unique, beautiful daughter was cruelly taken from us on Saturday night.
"We are reeling from the news and don't know what to do or say.
"She had so much more to experience and to give this world but we are grateful that she got to experience so very much in her 17 years. She has left an indelible mark on the word and an unfillable chasm in our hearts.
"Hold your kids extra tight tonight and for now please leave us to work through things. We will shout when we need you. Jude, Rachel, Jed and Ike x (sic)"