Afeni Shakur, the former Black Panther who inspired the work of her son rap icon Tupac Shakur, has died. She was 69.
Deputies and firefighters responded to a 911 call to her home in Sausalito, California, on Monday night and rushed her to hospital.
Medics tried to revive her for about an hour but "she had in fact died from what is believed to be some kind of cardiac event," Marin County Sheriff's Lieutenant Doug Pittman said.
Born Alice Faye Williams, Ms Shakur changed her name when she became politically active in the 1960s and joined the Black Panther movement.
By 1971, she was pregnant and jailed, accused of conspiring to bomb New York City landmarks.
Her son was born soon after the charges were dismissed and she named him Tupac Amaru, after the last Incan emperor who led a rebellion and refused to surrender to Spanish conquistadors.
As Afeni Shakur bounced from New York City to Baltimore to California, becoming addicted to drugs as a single mother of three children, she enrolled Tupac in arts schools and other programmes where he honed the musical and acting skills that would make him a hip-hop icon.
"Arts can save children, no matter what's going on in their homes," she said in a 2005 interview. "I wasn't available to do the right things for my son. If not for the arts, my child would've been lost."
Afeni Shakur left a deep impression on her son, helping to shape a world view that later made him stand out among other young rappers, with songs reflecting his own rebellious attitude toward racism, poverty, violence and other social problems.
Tupac, in turn, revered his mother, praising her in his 1995 elegy Dear Mama, a hit song many fans recalled on Tuesday in tweets and posts.
"You are appreciated," he tells her. "Ain't a woman alive that could take my mama's place."
Tupac Shakur died in a still-unsolved drive-by shooting in 1996 at the age of 25. Conspiracies about his killers flourished but his mother considered them a waste of time.
"We decided to deal with the living. This is justice for me," she said in 2005. "I need to do what God has put in front of me to do and it ain't trying to figure out who killed Tupac."
For the last two decades of her life, Afeni Shakur focused on keeping her son's legacy alive while managing his musical catalogue.
She opened the Tupac Amaru Shakur Centre for the Arts in Georgia - a project focused on helping at-risk youth that is now defunct.
She also co-produced a Broadway musical Holler If Ya Hear Me that used his songs - including Me Against the World, California Love and Keep Ya Head Up - to tell an original story by Todd Kreidler about two young men dealing with life and tragedy in a mid-western industrial city. It closed quickly in 2014 after playing just 38 performances.
She served as executive producer on a film about Tupac Shakur's life All Eyez on Me, which is set to be released in the autumn with Danai Gurira playing her son.