Updated

Major League Baseball umpire Wally Bell, who worked the NL playoff series between the Pittsburgh Pirates and St. Louis Cardinals this month, has died. He was 48.

Major League Baseball confirmed Bell's death Monday. He died of an apparent heart attack in his home state of Ohio.

Bell worked the 2006 World Series and three All-Star games, including this year's event at Citi Field, where he was stationed at first base. A veteran of 21 big league seasons, he had also worked four league championship series since joining the major league staff in 1993.

According to Bell's biography on MLB.com, his proudest moment as a big league umpire was returning to the field after having open heart surgery in 1999.