It struck with the force of a Category 2 hurricane but without the usual days of warning and time to prepare. Monday’s derecho, the violent thunderstorm complex that unleashed winds over 100 mph in parts of Iowa, has devastated scores of communities in the Hawkeye State. Cedar Rapids, a city of more than 130,000 people, was among the hardest-hit areas.

Dispatches from Cedar Rapids reveal a disaster zone, with damage to most homes and businesses, some severe; trees and wires down everywhere; roads blocked and hospitals overrun.

“This is a greater impact than we’ve ever seen in this community,” said Jeff Pomeranz, the Cedar Rapids city manager, as reported by Iowa Public Radio.

An article on the self-publishing website Medium laid bare the scope of the destruction.

“Nearly every home has damage. Most big trees in the city fell. Most local businesses are closed. Every business is damaged. Most roads are impassable,” wrote resident Ben Kaplan on Wednesday.

He further described “hours-long” lines at gas stations, sold-out generators and chain saws, spotty cellphone service, widespread gas leaks, downed power lines “in every neighborhood,” spoiled food, no trash pickup and no air-conditioning in the sweltering summer heat.

“Downtown bricks and glass litter the sidewalks,” he continued. “Plate glass windows shattered during the storm. Many businesses have been physically destroyed. All restaurants lost all of their perishables. Factories are closed. Offices are closed. The economy — the whole thing — is stopped.”

On Thursday, Iowa Public Radio reporter Kate Payne encountered a diabetic woman who hadn’t had insulin in two days and was running out of food. “Told me she’s thinking of eating the cat food,” she wrote on her Twitter feed. The woman, she later tweeted, was in line at a food distribution event at the public library, but Payne wrote that it “sounds like what she really needs is insulin.”

The storm has been blamed for four deaths, three in Iowa and one in Indiana.

Four days after the freak, fast-moving storm raked much of central Iowa, nearly 170,00 customers remained without power. About 600,000 people in Iowa and nearly 2 million in the Midwest lost power at the height of the storm as it raced from Nebraska to Indiana at speeds of up to 70 mph.

In Cedar Rapids, power may not be fully restored in some areas for another five to seven days, according to the Associated Press. As of Friday afternoon, about two-thirds of customers in Linn County, where Cedar Rapids is located, were still in the dark.

“Monday’s #derecho storm hit Cedar Rapids and communities across Iowa like a hurricane,” tweeted Rep. Abby Finkenauer (D-Iowa), who serves much of the state’s northeast, including Linn County. “We need more state, federal and National Guard assistance immediately to keep our folks safe and help out our hard-working local responders.”

After calls for help, Gov. Kim Reynolds (R) on Thursday mobilized the Iowa National Guard to assist Linn County’s recovery effort and has declared a state of disaster in 25 Iowa counties.

Speaking in Cedar Rapids at a news conference Friday, Reynolds said the destruction was “indescribable.” She committed to applying for a federal disaster declaration on Monday, which she said President Trump and Vice President Pence are ready to approve. This will provide financial assistance to affected homeowners and cover repairs for critical infrastructure.

“Iowans have endured the unimaginable over the last five months,” she said. “A worldwide pandemic that continues to change almost every aspect of how we live, work and interact with each other. On Monday, a massive weather event swept across the state like nothing we’ve ever seen in recent history.”

Some say the state government hasn’t acted quickly enough.

“It is outrageous that it took Governor Reynolds nearly a week to call in the National Guard when we know it will take weeks and months to recover,” wrote Stuart Appelbaum, president of the Retail, Wholesale and Department Store Union, in a statement. “Too many Iowans are suffering and it is not acceptable that they are living without electricity, many are unable to go work, downed trees block roads for families to get badly needed essential supplies — it’s horrific.”

Others have faulted the national media for not calling enough attention to the crisis.

“If you thought it mattered that, on Monday, nearly 150,000 Americans in this city had their lives literally paralyzed, in every way 21st-century life can be paralyzed, by a weather event so extreme its physical impact can be seen from space, you’d be wrong,” wrote Cary Jordan, an Iowa-based writer, in an essay titled “A Historic Failure in Journalism” on LinkedIn.

The storm has left behind an enormous agricultural toll, as the 100-plus mph winds flattened millions of acres of corn. Up to 43 percent of the state’s corn and soybean crop has suffered damage from the storm.

Steve Bowen, a meteorologist and head of catastrophe insight for the reinsurer Aon, said the damage toll to agriculture alone may reach billions of dollars.

“This has all the makings of a billion-dollar agricultural impact in Iowa and Illinois,” he wrote in a Twitter message. “With that said, it will take some time for farmers to determine how much of the downed crop is salvageable for harvest. When combined with the rest of the physical property damage to homes, businesses, vehicles, and infrastructure, it is entirely plausible that the derecho was responsible for a multi-billion-dollar economic cost on its own.”

The vicious windstorm came as a surprise on a morning when most of Iowa was predicted to see very isolated severe weather. The National Weather Service Storm Prediction Center had issued a Level 1 out of 5 “marginal risk” of severe weather for most of Iowa just a few hours before winds began gusting upward of 90 mph in the central part of the state. Storm warnings were issued as the storm complex barreled eastward, but most Iowans only had 30 to 45 minutes of lead time.

Once the storms began their violent march to the east, the Storm Prediction Center issued a dramatic upgrade in its storm outlook to a Level 4 out of 5 “moderate risk” from central Iowa east to Chicago, where wind gusts topped 70 mph. In areas to the east of the Iowa cornfields, the forecast was considered a success.

Matthew Cappucci contributed to this article.