The stadium is said to have been demolished in June 1999, but that's when the Mariners moved out, it imploded in March 2000, as the dead link on the page points out.
Original text:
"The Kingdome had a baseball capacity of 58,850, and was also home to the NFL's Seattle Seahawks before it was demolished in June 1999."
Action taken:
Date corrected.
Revised text:
"The Kingdome had a baseball capacity of 58,850, and was also home to the NFL's Seattle Seahawks before it was demolished in March 2000. Following the implosion, Seahawks Stadium was built on the site; the new arena opened for football in 2002."