L'Wren Scott has reportedly been found dead in her New York apartment.
The 49-year-old designer was found hanged to death by her assistant this morning at around 10am, Eastern time, according to multiple sources.
The designer and model had been dating The Rolling Stones lead singer Mick Jagger for 13 years.
A spokesperson for Mick, who is currently on tour in Australia, said the singer was 'completely shocked and devastated' when he heard the news.
The Utah-native reportedly text her assistant, asking her to come to her apartment, at around 8.30am this mornning.
Police do not suspect foul play but are awaiting the results of a report by the Medical Examiner's Office.
A spokesman for the British Fashion Council said: "We are deeply saddened at the news of L'Wren Scott's tragic death.
"She was an iconic woman who inspired so many, and a designer whose contributions to the fashion industry were both extraordinary and unique.
"She will leave behind an exceptional legacy however we are so incredibly proud to have had her in our midst. At this sad time our thoughts are with her friends and family."
Bianca Jagger, Mick's ex-wife, has tweeted her condolences following the tragic news: "Heartbroken to learn of the loss of the lovely and talented L'Wren Scott. My thoughts and prayers are with her family. May she rest in peace".
Fellow NYC-based designers Carly Cushnie and Michelle Ochs, founders of label Cushnie et Ochs, took to Twitter to express their sadness at L'Wren's passing: "RIP L'Wren Scott, so sad to lose a beautiful strong female designer".
Marc Jacobs also tweeted his shock and grief following the news: "Rest in peace, L'Wren Scott. You'll forever be missed."
Rush actress Olivia Wilde tweeted: "L'Wren Scott was brilliant, elegant, kind, and generous. Shit. My heart goes out to her loved ones. What a tragedy."
Actress Emmy Rossum has also tweeted: "So sad to hear of the death of L'Wren Scott. What a beautiful woman and an incredible designer."
The news comes just weeks after the world famous designer cancelled her London Fashion Week show at the very last minute.
Famous fans of L'Wren's impressive body of work include Sarah Jessica Parker, Nicole Kidman and Christina Hendricks and the fashion icon was rumoured to be designing Angelina Jolie's wedding dress.
If you have been affected by this article please call Samaritans on 08457 90 90 90 (UK) 1850 60 90 90 (ROI) or visit www.samaritans.org to find details of the nearest branch. Samaritans is available round the clock, every single day of the year, for anyone who is struggling to cope.