Pulitzer Prize-nominated author and poet Maya Angelou was taken to the hospital Sunday for as-yet-unknown causes, TMZ.com reported.

Angelou, 81, was in Los Angeles to be honored at the BraveHeartAwards, celebrating women who have made changes in their professional fields. Other celebrities scheduled to attend the weekend-long ceremonies were Mariel Hemingway and Courteney Cox, according to the awards' site.

Angelou gained worldwide fame with her literary activism in the Civil Rights movement and for works like "I Know Why the Caged Bird Sings," an autobiographical account of her childhood and early teenage years. The book recounted Angelou's experience with sexual abuse and rape at the age of 8 at the hands of her mother's boyfriend.

She was nominated for the Pulitzer Prize for her 1971 poetry collection, "Just Give Me a Cool Drink of Water 'Fore I Diiie."