SAN JUAN — Sleepless Puerto Ricans awoke Wednesday knowing to expect a thrashing from the most ferocious storm to strike the island in at least 85 years. They met nightfall confronting the ruin Hurricane Maria left behind: engorged rivers, blown-out windows, sheared roofs, toppled trees and an obliterated electric grid that cut power to every one of the island's 3.4 million people.

Even though authorities had barely begun to assess the damage Wednesday evening, the scope of the catastrophe was evident, even if in snippets.

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The capital city of San Juan got a walloping. Evacuees at a sports arena had to leave a ground floor when the roof sprang a leak, a space rocket adorning the park at a science museum keeled over and the roof of a radio station blew off, though it kept broadcasting despite the damage.

"We will find our island destroyed," Abner Gómez, Puerto Rico's emergency management director, warned before Maria's eye had cleared the island. "It's a system that has destroyed everything it has had in its path."

Less was known about the damage beyond the densely populated San Juan region, although it was certain to be just as horrific, particularly on the normally idyllic southeast coast where Maria came ashore. The National Hurricane Center on Wednesday night warned that "catastrophic flash flooding was occurring over portions of Puerto Rico."

"It's a nightmare. This is my first hurricane," said Leyda Anqueira, a 22-year-old college student who rode out the storm in her small isolated community of Palma Sola east of San Juan, where an angry river destroyed the only bridge to her neighborhood. "We're cut off. There's no way to get to the highway."

Generation after generation of Puerto Ricans have heard terrifying tales about the previous big ones: Hugo in 1989, Georges in 1998 and San Ciprián in 1932, the last Category 4 storm to devastate the island. Now, they have a horror hurricane of their own.

"Our building looked like it was hit by a bomb," Aris García said of the destruction to her home on Ashford Avenue, a tourist strip in San Juan's Condado neighborhood.

"Water got inside from everywhere," said Jan González, who walked out with García hand-in-hand after the storm. "We felt we were on the Titanic. This is disastrous."

Maria's only solace: When it arrived, around 6:15 a.m. near the southeastern coastal town of Yabucoa, it was no longer a Category 5, its winds down to a still-catastrophic 155 mph after leaving at least nine dead across the Caribbean. Maria departed as a Category 3 just before 2 p.m. near Barceloneta, west of the metropolitan San Juan area.

For days, the government warned Puerto Ricans of Maria's potential force. But that didn't diminish residents' awe Wednesday that so many dire predictions — wrong for Hurricane Irma, which only skirted the island two weeks ago — came true.

"What I'm seeing is incredible," said retiree Rosita Galguerra, 66, who was riding out the storm with her husband in the Río Piedras neighborhood of San Juan. "The rain is horizontal and all the trees are on the ground.

"The house is trembling — and my house is made of concrete with a concrete roof. The winds are like out of a horror movie and it's gusts, gusts, gusts. The island is going to be completely destroyed."

And just because Maria's core was gone didn't mean her wrath was over. Rains that could result in flash floods and mudslides are forecast to continue until at least Saturday. Gómez, the emergency director, implored people to stay home through Friday, to let crews assess impassable roads and felled power lines. They planned to head out without communication Wednesday night, blind to what they'd find.

His appeal for people to sit tight seemed unlikely to take hold. Puerto Ricans ventured outside before hurricane winds had fully died down, to remove debris and survey the streets themselves, gawking at ripped out trees, strewn pieces of zinc roofs and power lines that lay horizontal on the ground.

"The truth is the danger continues," Gov. Ricardo Rosselló told the island's largest newspaper, El Nuevo Día. "It's going to keep raining hard. Flood zones are at critical levels. We're still going to have a full day of rain."

Late in the afternoon, Rosselló imposed a 6 p.m. to 6 a.m. curfew, citing security concerns.

Northwest of Puerto Rico, Maria — as of Wednesday night a Category 2 storm with 110 mph winds— was also expected to dump lethal amounts of rainfall on the Dominican Republic and Haiti while heading toward Turks & Caicos and the Bahamas later in the week. If the storm continues on its predicted path, it should not pose a danger to Florida but it was still too early to completely rule out some effects along the East Coast of the United States.

Maria hit Puerto Rico as a Category 4, the strongest storm to make landfall in Puerto Rico since the San Ciprián hurricane killed more than 200 people in 1932. The storm made official landfall on the island's southeastern tip and least-developed coastline. The region is home to nature preserves, some beach resorts and sugar plantations.

Forecasters said Maria went through an eyewall replacement cycle just offshore of Puerto Rico. That slightly weakened the storm but nearly doubled the width of its hurricane wind field, extending out 60 miles. On a tiny island just 35 miles wide, that likely brought Maria's stronger right quadrant into San Juan, where early morning winds screeched like a wounded hyena.

The storm hit the U.S. territory more than a week after another major hurricane, Irma, rolled through the Caribbean, crossed the Florida Keys and slammed into the state's Gulf Coast, leaving more than 40 dead. Puerto Rico avoided a direct Irma hit, but its winds nevertheless knocked out power to thousands – 70,000 still had no electricity as Maria approached.

Across Puerto Rico throughout the day, snapshots of the damage emerged through press coverage and social media. Surprisingly, many residents still had cell service in the San Juan region.

Local radar stopped functioning before 6 a.m. El Nuevo Día reported a portion of a police station collapsed. Floodgates were opened at La Plata river, which could endanger nearby communities, according to the Primera Hora newspaper. Puerto Rico's power company estimated its worst-case scenario had materialized: 100 percent of the island was without electricity.

Video footage showed the muddy Guayama River overflowing and rushing in a brown torrent down streets. One photo on social media showed families wading through brown chest-deep water in Utuado in the central part of the island.

More than 700 evacuees who sheltered at the Roberto Clemente Coliseum sports arena had to clear the bottom floor because of a roof leak, while staffers used a chain to keep the doors from blowing open. By the end of the morning, the shelter had no power or running water and the roof was "in pieces" although structurally sound, according to San Juan Mayor Carmen Yulín Cruz.

"It's been a difficult night, and it's been a difficult day," Yulín told WKAQ-AM, a local Univisión station. "The country we knew yesterday has changed."