Today is a very sad day. Nelson Mandela -- former South African president who led the snit-apartheid movement -- has died at the age of 95. 

"Our nation has lost his greatest son," stated South African President Jacob Zuma. "Our people have lost their father."

Mandela, who was imprisoned for 27 years before leading his country, was South Africa's first black president, and has inspired activists around the world due to his humanitarian work.

Mandela's health was on a decline in recent years, frequently being hospitalized for a chronic lung infection.

Stars like Fergie, Oliva Wilde, Rihanna and Kendrick Lamar shared their condolences on Twitter.

RIP Nelson Mandela.