The National Weather Service said late Thursday that Hurricane Lane brought more than 19 inches of rain to parts of Hawaii's Big Island during a 24-hour period, flooding parts of the island. The agency warned some areas could see up to 30 inches of rainfall before the hurricane passed.

The Waikulu River, the longest river in Hawaii, swelled up by the lashing rains, and forced people living on the banks to evacuate. Hawaiian Airlines cancelled all Friday flights by its commuter carrier, Ohana by Hawaiian, while United Airlines cancelled flights to and from Maui on Friday.

"Excessive rainfall associated with this slow-moving hurricane will continue to impact the Hawaiian Islands into the weekend, leading to significant and life-threatening flash flooding and landslides," the National Hurricane Center warned Thursday.

Though the hurricane weakened as it moved closer to Hawaii Thursday, it triggered landslides that forced officials to close some roads including the H-3 Freeway and parts of Route 19.

"Highway 19 is partially blocked in multiple areas due to landslides. Police and Department of Transportation crews are responding to the rock slides, debris and water on the roadway. This roadway is extremely hazardous," Hawaii County Civil Defense Agency said.

"Lane, while it's been downgraded, is wide and very moist and it's going to hang around for a while," said Honolulu mayor Kirk Caldwell, CBS News reported.

"Lane has the potential of bringing the state of Hawaii serious and perhaps record damage," AccuWeather hurricane expert Dan Kottlowski said.

Power outages were reported in several parts of Hawaii, including the Kahului Airport in Maui County on Thursday evening. "People should be prepared for power outages, coastal flooding, beach erosion, downed trees and major travel disruptions," said AccuWeather senior meteorologist Alex Sosnowski.

Several buses rescued residents, including five people from a flooded house in Hilo, and took them to shelters Thursday. All schools in Hawaii suspended classes while many state employees were asked to stay home, BBC reported.

The National Weather Service (NWS) issued a flash flood warning for the Big Island for Thursday. It warned people to avoid unnecessary travelling as the situation could get worse.

"All motorists and residents of affected areas are urged to use extreme caution and be aware of flooding conditions. This is a very dangerous situation and heavy rains are expected to continue,” the Hawaii County Civil Defense Agency said.

Several residents stocked up on supplies and boarded up homes Thursday. “Preparations to protect life and property should be rushed to completion. Life threatening impacts are likely in some areas as the hurricane makes its closest approach,” NWS said.

President Donald Trump declared a state of emergency in Hawaii on Wednesday night. “I have authorized an emergency disaster declaration to provide Hawaii the necessary support ahead of Hurricane Lane. Our teams are closely coordinating with the state and local authorities,” Trump tweeted.

“This emergency proclamation will provide relief for disaster damages, losses and suffering caused by Hurricane Lane. The proclamation also serves to protect the health, safety and welfare of Hawaii residents and visitors,” Hawaii’s Governor David Ige signed an emergency proclamation late Wednesday.