All along the main street, buildings are crumpled beyond recognition, roofs punched in and pancaked. Historic mud-brick houses in its walled old city are pounded to dust. Saada, the birthplace of Yemen's Shiite rebels, has been one of the most densely bombed cities in Yemen during the past 19 months of airstrikes by Saudi Arabia and its allies.

Residents are now struggling to bring some signs of life back to the city, high in the mountains of Yemen's north.

The bombardment here eased relatively in recent months; the coalition may have hit everything worth hitting in the city, residents theorize, so some of the thousands who fled during the past year have decided to take their chances and return home.

But they are dealing with devastated infrastructure — a single, overburdened hospital, almost no electricity — and constant fear. The nearby countryside is still often hit by strikes, and Saudi-backed militias threaten a ground assault on the area. Drivers avoid coming close to pickup trucks carrying rebel fighters, fearing a missile may come streaking down.

"The more crowded a place is, the more we are afraid of bombings," said Naglaa Fathi, a 15-year-old girl whose family returned recently. After bombings in May 2015 shattered the houses around theirs, her family fled to Khamr, a town further south. But they were tired of moving from house to house.

Now they're back in their home in Saada's Old City, though her parents moved out of their bedroom because "every time we look from the window, we see destruction," her mother Samira Mohammed said.

The destruction is extensive. In just the first weeks of the airstrikes in early 2015, around 1,170 structures were damaged or destroyed in Saada, according to the United Nations. As bombardment continued for more than a year, an estimated 40 percent of Saada's 50,000 residents fled. Many of those who remained literally dug holes in the ground to hide in and moved schools and hospitals into caves for protection.

It was here in Saada that the Shiite rebel movement known as the Houthis was born.

The city for centuries has been a center of the Zaydi branch of Shia Islam, which is found almost only in Yemen and makes up at least a third of the country's population. Saada was the seat of power of Imam al-Hadi Yahia, a 10th century religious leader who set up a Zaydi dynasty.

The Houthis arose when Hussein Badr Eddin al-Houthi founded a Zaydi revivalist movement known as the Believing Youth in response to the spread of Saudi Arabia's hard-line Wahhabi interpretation of Sunni Islam. He was killed by government forces in 2004, and his followers launched an insurgency. Yemen's strongman president, Ali Abdullah Saleh, waged a string of wars in Saada trying in vain to defeat the Houthis.

Then Saleh was ousted following a 2011 popular uprising. Three years later, the Houthis came storming out of the north and took over the capital, Sanaa, now allied with Saleh and the army units still loyal to him. Saudi Arabia and its allies launched their air campaign in early 2015 to defend the internationally recognized president, Abed-Rabbo Mansour Hadi. The coalition and the United States accuse Iran of arming the rebels, a claim Tehran and the Houthis deny.

Ever since, the country has been ravaged by fighting and strikes. Saada appears to have come in for particularly heavy punishment.

Power stations have been knocked out. Roads into the city are dotted with burned-out husks of fuel tanker trucks struck by missiles before they could deliver their cargo. Fuel for generators is hard to find even on the black market. The city's only hospital relies on fuel smuggled in by small cars to avoid the warplanes' attention.

In and around Saada, 178 bridges, 13 power stations, 17,193 houses, 173 schools, 118 markets and 696 farms have been destroyed or damaged, according to the Houthi-affiliated Legal Center for Rights and Developments.

The center says it has documented 2,262 civilians killed in Saada from March 2015 to March 2016, including 397 children, though the figures could not be independently confirmed.

Inside Saada's Old City, surrounded by a 3,000-meter-long ancient wall, historic mud-brick houses are blasted to powder or in some cases sliced in half, revealing abandoned bedrooms and kitchens inside.

The more than century-old souq, or market, lies in ruins, deserted except for stray dogs and cats. Abdel-Nasser Bashir, an antiques dealer, recalled how strikes last year sparked a fire that swept through his shop, a nearby dried fruits store, a tailor's, a currency exchange office and a restaurant.

"What does the market have to do with the war?" he said. "They want to get rid of the Yemeni people."

Despite the bombardment, Houthi fighters still have an open presence, with checkpoints at entrances to the Old City and along main roads. Houses of many of the top Houthi leadership are in the city — most of them now leveled by strikes.

The movement's leader, Abdel-Malek al-Houthi, is believed to be hiding in the nearby Marran mountains, the same refuge he took in past wars. Last week, the coalition accused the Houthis of firing a rocket from the Saada area toward Mecca, a claim the rebels deny.

With some residents returning, there have been new signs of life. Some shops and restaurants have reopened. The main market for qat, a stimulant leaf that Yemenis chew addictively, is once again busy with crowds of men.

Local authorities are trying to project some normalcy. UNICEF has launched a campaign to get students and teachers back into schools. But most still stay away, fearing airstrikes.

"They have hit the schools, the seats, and the chalkboards, while the teachers are now displaced, and can't come back," said the head of the education department, Abdel-Rahman al-Dharafi.

"The biggest barrier is fear," he said.

The Saudi-led coalition has often said schools are used by the Houthis as training grounds for child soldiers — the reason it gave, for example, in a September strike on a religious school in the border town of Haydan, near Saada, that killed 10 children.

Al-Dharafi denied schools are used for child soldiers, though UNICEF has said both the Houthis and their opponents recruit children as fighters.

Al-Gomhouri, Saada's only hospital, was built for 20-30 patients but it has added 150 more beds. Still, it gets some 500 patients a day and up to 100 war-wounded. Many of the patients are malnourished children brought from the countryside where there are no health facilities.

There are shortages of medicine and staff, compounded when the international aid group Doctors Without Borders withdrew its team over the summer for security reasons, said the hospital's head, Mohammed Hagar. "The hospital is under heavy pressure," he said.

Because of the difficulty of movement between towns in Saada province, an estimated 4 percent of pregnant women develop complications and are at risk of death, according to Ghamdan Mofarreh from the United Nations Population Fund.

"Stress and fear are prime causes of miscarriages ... women can't bear it," he said.