Complex sentence: The aquarium was opened in September 1955, closed in 31 May 1991, reopened as World of Aquarium in 1991 and Fort Canning Aquarium in 1993, closed for the last time in 1996 and demolished in 1998.
Split into simpler sentences: The aquarium was opened in September 1955, closed in 31 May 1991, reopened as World of Aquarium in 1991 and Fort Canning Aquarium in 1993. The Aquarium closed for the last time in 1996 and subsequently demolished in 1998.