Simplify the following text for a Grade 12 native English-speaking person.
Original: In February 2011 , new symptoms related to congestive heart failure caused her to be admitted into Cedars-Sinai Medical Center in Los Angeles for treatment , where she remained until her death at age 79 on March 23 , 2011 , surrounded by her four children .
Simplified: In 2004 , she was diagnosed with congestive heart failure ; in 2009 she underwent cardiac surgery for it ; in early 2011 , new symptoms related to congestive heart failure caused her to be admitted into Cedars-Sinai Medical Center for treatment . Taylor died on March 23 , 2011 , surrounded by her four children at the same medical center in in Los Angeles , California , at the age of 79 .