Typhoon Sinlaku — the strongest tropical cyclone on Earth this year — relentlessly hammered a pair of remote U.S. islands in the western Pacific Ocean early Wednesday local time with extremely powerful winds and heavy rain, with residents reporting tin roofs being torn apart. 

Authorities said they were in the early stages of assessing the damage left by the storm, which made landfall on Tuesday. Electrical outages were widespread and roads impassible in some areas, with images and video from the islands showing uprooted trees, downed power lines and flooding. 

The American Red Cross was working with local agencies to shelter more than 1,000 people across multiple islands, a spokesperson for the organization told CBS News. No deaths have been reported so far.

The typhoon had sustained winds of up to 150 mph, equating to a strong Category 4, when it hit the islands of Tinian and Saipan of the Northern Mariana Islands, according to the National Weather Service. Its maximum wind speeds wavered somewhat after landfall and have since dropped to 125 mph, as the storm tracks north.

Sinlaku will start to curve toward sparsely populated volcanic islands in the far northern Marianas, forecasters said.

Sinlaku is expected to continue weakening through the next few days, according to the weather service, passing west of the islands of Alamagan, Pagan and Agrihan through the latter half of the week. But officials still advised people to remain indoors Wednesday, as wind gusts up to 70 mph were ongoing in many areas while storm surge produced waves as high as 18 feet, the weather service said.

Jaden Sanchez, a spokesperson for the Saipan mayor's office, told the Associated Press that wind and rain persisted roughly 24 hours after the typhoon initially struck the island, but conditions were improving. Cleanup crews were seen clearing debris in blustery conditions on Saipan in a social media video posted by the mayor's office.

"I'm guessing anything that was made of wood and tin did not survive this," Glen Hunter told AP. Hunter grew up on Saipan and watched at least three tin roofs fly past his yard.

Hunter, who has weathered numerous typhoons, told AP this felt like the strongest yet. Rain was seeping into every crevice of his concrete home, he said.

"It was a losing battle because the rain was coming through everywhere," he said. "Every house is just flooded with water, no matter what type of structure you're in."

Saipan Mayor Ramon "RB" Jose Blas Camacho told AP that parts of the island saw extensive flooding. He said Tuesday that Sinlaku was "hitting us hard."

"It's so difficult for us to respond with this heavy rain, heavy wind to rescue people," the mayor said. "Objects are just flying left and right."

Camacho told AP some people were rescued, as the typhoon toppled trees and caused structures to collapse.

Video shared by AP ahead of the typhoon's arrival showed its early impacts on Saipan, as Sinlaku hovered offshore, launching fierce winds and rain toward the island. Before arriving on land, the storm had become "nearly stationary" about 30 miles off the coast of the archipelago for several hours, forecasts showed. Its slow pace raised concerns about how long the storm would linger in the region, and the amount of damage that could cause.

Tropical force winds and torrential rainfall led to flash flooding on Guam, a U.S. territory that's a critical hub for U.S. forces in the Pacific, home to three U.S. military bases and about 170,000 people. Wind gusts peaked at 88 mph Tuesday night local time on the island — with consistent wind gusts between 70 and 80 mph recorded through the night, according to the National Weather Service. Tropical-storm-force winds were forecast to continue through Wednesday afternoon, according to Guam's Joint Information Center.

"Even though the closest point of approach has passed, damaging winds will persist across the island, posing ongoing risks to public safety, infrastructure, and power lines," the center said in an advisory, which urged people to remain indoors and out of the water.

U.S. military officials warned personnel to shelter in place. The military controls about one-third of the land on Guam.  

The Guam Department of Education closed schools Tuesday and Wednesday, and the information center said they would remain shut until the governor declares conditions are safe for classes to return. The center also said Guam's water authority was "aware of multiple power outages throughout the island as a result of the super typhoon."

Typhoon warnings remained in effect for the Marianas islands of Rota, Tinian, Saipan, Alamagan, Pagan and Agrihan as of Tuesday evening, according to the weather service. Guam remained under a tropical storm warning and typhoon watch, the weather service said.

In the Southwest Pacific, "typhoon" is used to describe a tropical storm that forecasters would call a hurricane in the U.S. When a typhoon's maximum sustained winds rise above 150 mph, it becomes a "super typhoon."

Sinlaku's maximum wind speeds peaked at 180 mph as the typhoon traveled over the open ocean on Sunday, making it the most powerful storm to develop so far this year, after typhoons Narelle and Dudzai.

On Sunday, President Trump approved emergency disaster declarations ahead of the forecasted storm for Guam and the Mariana Islands.

In May 2023, Super Typhoon Mawar struck Guam as a powerful Category 4 storm, hitting the island with destructive and powerful winds and heavy rain.

In Saipan, the largest of the Northern Mariana Islands, residents are still recovering from the 2018 Super Typhoon Yutu, Hunter told the AP.

And tourism-dependent Saipan — the site of one of World War II's bloodiest battles in the Pacific — was still reeling from Yutu when the COVID-19 pandemic hit, Hunter said. The economy has yet to rebound, he said.

Yutu destroyed 85% of the Saipan campus of Northern Marianas College, said the school's president, Galvin Deleon Guerrero. The institution secured $100 million in grant funding to rebuild.

"Just as we were finally beginning to recover and rebuild, we get hit with this," he said. "Climate change is real."

He said he worries about people still suffering from the post-traumatic stress of Yutu.

"We are an incredibly resilient people," he said, noting that he's Chamorro, the Indigenous people of the Mariana Islands. "But just because we're resilient doesn't mean that we should be subjected to this on this frequent basis."

Eyewall replacement exhausted typhoon

Before its strength began to dip, Sinlaku was so intense as a super typhoon that it underwent an eyewall replacement cycle, said CBS News meteorologist Nikki Nolan. Radar data show the phenomenon happened sometime in the last 24 hours, while the then-super typhoon tracked toward the Marianas. 

Eyewall replacement cycles are often seen in the mightiest tropical storms. In the case of Sinlaku, a new eyewall formed around the original one, prompting the original to collapse on itself and grow in size. Nolan said this was the typhoon's "way of burning itself out," and the process caused it to slow down and drop to a Category 4 storm.