Mick Jagger's longtime girlfriend and fashion designer L'Wren Scott was found dead on Monday after she apparently hanged herself and Jagger opened up on social media about her passing.

In a Facebook post, Jagger composed a short note on Scott's passing, in which he wrote, "I am still struggling to understand how my lover and best friend could end her life in this tragic way."

The Rolling Stones' frontman continued, "She had great presence and her talent was much admired, not least by me." He ended the short post saying that the outpouring of support "touched" him and said "I will never forget her."

As previously reported, the 49-year-old fashion designer was found in her Manhattan apartment after she apparently committed suicide by hanging herself.

Scott, who had been dating Jagger since 2001, left no suicide note and police have said they do not suspect foul play in her death.

In the wake of the devastating news, The Rolling Stones Wikimedia Commons