HONOLULU (AP) — Crews on Tuesday began evaluating damage from a surprise downpour that sent floodwaters raging through a neighborhood near downtown Honolulu — the latest bout in a series of storms and flooding that have pummeled the state over the past two weeks.

Residents along Oahu’s North Shore were cleaning up from the worst flooding to hit Hawaii in two decades when a storm Monday unleashed several inches of rain on the southern part of the island. Reddish-brown torrents gushed along roads in the Manoa Valley, sweeping away parked cars and swamping much of the neighborhood.

“I was shocked to see how much flash flooding there was in my area,” said resident Andrew Phomsouvanh, referencing video he recorded showing streets transformed into rapids. “The water just keeps coming.”

As residents like Maile Mills assessed the damage, she realized there was nothing she could do to save her Honda Civic, submerged as the floodwaters reached the car’s door handles. “It looked like rubber ducks in a pond,” she described. “All the cars started to float.”

The ferocity of Monday’s downpour even took National Weather Service meteorologists by surprise. They recognized the potential for heavy rain from a powerful winter storm system called a “Kona low,” but their forecasts struggled to predict the extent of moisture remaining in such systems, said forecaster Cole Evans.

Flood watches were still in effect for parts of Maui and the Big Island as the Kona low system began to drift eastward. While there were no immediate reports of fatalities or serious injuries, authorities confirmed that hundreds of homes on Oahu had been damaged by storms.

Gov. Josh Green estimated earlier that the overall cost of damage could easily top $1 billion, referencing impacts on airports, schools, and infrastructure across the islands.

Locals relied on community support, with volunteers emerging to sort donated supplies for distribution, showcasing resilience despite the devastation. “Most of us have not seen something that just keeps going like this,” said Molly Pierce from the Oahu Emergency Management Agency. “We feel like we keep getting punched down. But we’ll keep getting back up.”

Currently, experts attribute the increasing intensity and frequency of heavy rains in Hawaii to human-caused global warming, positioning this unexpected weather event within broader climate challenges facing the region.