According to WWE.com, the Paul Bearer died on March 5, 2013. He was 58 years old.
WWE released a statement:
WWE is saddened to learn of the passing of William Moody, aka Paul Bearer. Moody made his WWE debut in 1991 as the manager of The Undertaker and went on to become a memorable part of WWE over the course of the next 20 years.
Our deepest condolences go out to Moody's family, friends and fans.
WWE fans tweeted their respect for the wrestling manager and former wrestler.
He started with wrestling in 1991, and became one of the most beloved and recognized personalities. Paul Bearer's profile on WWE