Happy Gas Smash!, also known as Destroy Happy Gas!, is a mission in Grand Theft Auto 2 given to protagonist Claude Speed by Johnny Zoo of the Yakuza. The mission is available from the left of the two yellow Yakuza phones in Funabashi, Downtown District.
The Loonies have not paid Johnny back from a previous deal. He tells Claude to retrieve the money from the Loonies, then return. When Claude arrives at the meet, the Loonies double-cross Johnny and attack Claude. Furious, Johnny orders Claude to arm an Ice-Cream Van with a bomb, break into the Asylum and destroy the Happy Gas Tanks.
The reward for completing the mission is $40,000.