In Roland Emmerich's big-budget catastrophe extravaganza, which rumbles and roars through German cinemas starting Thursday, massive flood swells crash through the concrete valleys of New York City, destroying everything in their path. This big city drama, however, was actually inspired by a somewhat similar but smaller-scale occurrence in a modest German town.

Pirna, population 40,448, experienced its own raging waters in August 2002, when torrential rains caused several major German rivers and many tributaries to swell over their banks, ravaging cities and towns and causing millions of dollars in damage in the century's worst flooding.

For most German towns, the drama ended after the waters subsided and clean up was completed months later, but for the eastern German town of Pirna, the flood is being immortalized on celluiloid, sort of.

Michael Möbius, a Pirna native who lives in Los Angeles and works as an artist and 3-D photographer, was visiting home at the time of the floods, and had his special camera with him. As the waters bolted through town, Möbius captured them on film and took them back to Hollywood.

There he showed them to his friend Donald Fazel, a computer animator who was providing the special effects for Emmerich's disaster film, in production at the time. When Fazel saw the 3-D snaps, he realized he'd struck gold, since he didn't know of any comparable three-dimensional recordings of flood waves. He then set about to take Pirna's drama to the big screen.

Digitalized and increased by a factor of one hundred, little Pirna's mighty ripples became giant tsunamis striking terror in the heart of New York City.

As of Thursday, Pirna's residents can watch their one-time waves roar to life again. This time, though, they can dispense with the sandbagging.