It was Asia's answer to Hurricane Katrina—though with a reported 100,000 killed, it was many times more deadly.
Packing winds upward of 120 miles an hour (193 kilometers an hour), Cyclone Nargis became one of Asia's deadliest storms by hitting land at one of the lowest points in Myanmar (also called Burma) and setting off a storm surge that reached 25 miles (40 kilometers) inland.
"When we saw the [storm] track, I said, 'Uh oh, this is not going to be good,'" said Mark Lander, a meteorology professor at the University of Guam.
"It would create a big storm surge. It was like Katrina going into New Orleans."
Forecasters began tracking the cyclone April 28 as it first headed toward India. As projected, the storm took a sharp turn eastward. But it didn't follow the typical cyclone track, which leads to Bangladesh or Myanmar's mountainous northwest.
Instead, the cyclone swept into the low-lying Irrawaddy River Delta in central Myanmar. The result was the worst disaster ever in the impoverished country.
It was the first time such an intense storm is known to have hit the delta, said Jeff Masters, co-founder and director of meteorology at the San Francisco-based Web site Weather Underground.
He called it "one of those once-in-every-500-years kind of things."
"The easterly component of the path is unusual," Masters said. "It tracked right over the most vulnerable part of the country, where most of the people live."