US musician and rapper Coolio performs during the Night of the Proms in Lodz, Poland, 22 March 2014. EPA/GRZEGORZ MICHALOWSKI POLAND OUT 
Coolio, born Artis Leon Ivey Jr., was best known for his 1995 single "Gangsta's Paradise," from an album of the same name.
That song, a massive hit featured in the film Dangerous Minds, won a Grammy Award for best rap solo performance the following year.
The rapper died at about 5 p.m. pacific time (8 p.m. EDT) at a local hospital, his manager Jarez Posey told the Times. Posey told the paper that Ivey had earlier been found unresponsive in the bathroom of a friend's home.
There were no immediate reports on the cause of death.
Ivey, who was born in Pennsylvania in 1963, began performing as part of the West Coast hip-hop scene after moving to Compton, California.
He released his debut album, "It Takes a Thief", in 1994, scoring a Top Ten hit with the single "Lakeside."
(Reporting by Sharon Bernstein and Dan Whitcomb; Editing by Christian Schmollinger and Christopher Cushing)