This coaster debuted as "Thriller" on the German funfair circuit in 1986, under the ownership of Oscar Bruch and toured the country until 1997, with a short spell on loan to the Gröna Lundamusement park for the 1996 season. Its last fair was the Hamburger Dom of November/December 1997, after which it was taken to the now-defunct Six Flags AstroWorld in Houston, Texas. It was assembled at Six Flags AstroWorld in Houston late in 1997. The roller coaster opened at Six Flags AstroWorld on March 14, 1998 and was renamed Texas Tornado. This coaster had very positive reviews from guests but when summer hit, the heat and humidity seemed to disrupt operation. On very hot days the coaster suffered a lot of downtime. "Texas Tornado" continued to operate there in the 1999 and 2000 seasons with a lot of downtime on the hotter days. It seemed to run decently on milder and cooler days. At the end of the 2000 season, Six Flags decided to remove the ride but it stayed at AstroWorld in 2001 but did not operate that season. Early in 2002, it was moved out of Six Flags AstroWorld and into storage. In 2003, Texas Tornado was moved to Six Flags Discovery Kingdom and some track modifications were made by Premier Rides. The most significant was increasing the elevation of the first two loops. The effect of this change would be reducing the Thriller's top speed and lowering the g-forces during the first two loops. It was assumed that the mild weather would enable the coaster to run better. It was then renamed Zonga. Zonga then operated for two years at Marine World. Unfortunately, operation continued to be inconsistent. Zonga regularly opened about two hours after the park and had frequent breakdowns. The ride wasn't very attractive because of its location and appearance. There have been many malfunctions, which eventually led to Six Flags again closing down the ride. There have also been many complaints about the ride being "bumpy". The ride ran for much of the 2004 season but stood silent for the 2005 season and was removed at the beginning of the 2006 season, leaving a large empty concrete area at the front of the park. Zonga was disassembled and moved to the Discovery Kingdom parking lot where it sat throughout the 2006 season. The new coaster for 2008—Tony Hawk's Big Spin, now known as Pandemonium since 2011. Pandemonium erected on the pad that Zonga used to occupy. Now since 2012 another new ride has been established Zonga was then bought in 2008 by the Aguascalientes State government in Mexico, for its use in the famous San Marcos National Fair, where it has been renamed "Tsunami".
Removal
From a news article published by a local newspaper on 23 October 2013, it was announced Tsunami would no longer operate in Mexico after La Feria de San Marcos ended in 2014. An idea was suggested to move the roller coaster to the Bad Wörishofen "Skyline Park" for the 2016 season. However, the move didn't occur and the roller coaster was dismantled in 2016.
