DERNA, Libya >> Search teams combed streets, wrecked buildings and even the sea Wednesday to look for bodies in a coastal Libyan city where the collapse of two dams unleashed a massive flash flood that killed at least 5,100 people.

The Mediterranean city of Derna has struggled to get help after Sunday night’s deluge washed away most access roads. Aid workers who managed to reach the city described devastation in its center, with thousands still missing and tens of thousands left homeless.

“Bodies are everywhere, inside houses, in the streets, at sea. Wherever you go, you find dead men, women, and children,” Emad al-Falah, an aid worker from Benghazi, said over the phone from Derna. “Entire families were lost.”

Mediterranean storm Daniel caused deadly flooding Sunday in many towns of eastern Libya, but the worst-hit was Derna. Two dams in the mountains above the city collapsed, sending floodwaters roaring down the Wadi Derna river and through the city center, sweeping away entire city blocks.

As much as a quarter of the city has disappeared, emergency officials said.

Waves rose as high as 7 meters (23 feet), Yann Fridez, head of the delegation of the International Committee of the Red Cross in Libya, told broadcaster France24.

Teacher Mohammed Derna said he, his family and neighbors rushed to the roof of their apartment building, stunned at the volume of water rushing by. It reached the second story of many buildings, he said. They watched people below, including women and children being washed away.

“They were screaming, ‘Help, help,’” he said over the phone from a field hospital in Derna. “It was like a Hollywood horror movie.”

Derna lies on a narrow coastal plain, under steep mountains. The only two usable roads from the south take a winding route through the mountains.

Collapsed bridges over the river split the city center, further hampering movement.

Search teams went through shattered apartment buildings and retrieved the dead floating offshore in the Mediterranean Sea, al-Falah said.

Ossama Ali, a spokesman for an ambulance center in eastern Libya, said at least 5,100 deaths were recorded in Derna, along with around 100 others elsewhere in eastern Libya. More than 7,000 people in the city were injured.

A spokesman for the eastern Libyan interior ministry put the death tally in Derna at more than 5,300, according to the state-run news agency.

The number of deaths was likely to increase since teams are still collecting bodies, Ali said. At least 9,000 people are missing, but that number could drop as communications are restored.

At least 30,000 people in Derna were displaced by the flooding, the U.N.’s International Organization for Migration said.

The storm hit other areas in eastern Libya, including the towns of Bayda, Susa and Marj. Rescuers retrieved at least 150 bodies Wednesday from the sea off Bayda, bringing the death tally in the town to about 200, Ali said.

The startling devastation pointed to the storm’s intensity, but also Libya’s vulnerability. The country is divided by rival governments, one in the east, the other in the west, and the result has been neglect of infrastructure in many areas.

Ahmed Abdalla, a survivor who joined the search-and-rescue effort, said they were putting bodies in the yard of a hospital before taking them for burial in mass graves at Derna’s sole intact cemetery.

“The situation is indescribable. Entire families dead in this disaster. Some were washed away to the sea,” Abdalla said by phone.

Derna is 250 kilometers (150 miles) east of Benghazi, where international aid started to arrive on Tuesday.

Neighboring Egypt, Algeria and Tunisia, as well as Turkey, Italy and the United Arab Emirates, sent rescue teams and aid. The U.K. and German governments sent assistance too, including blankets, sleeping bags, sleeping mats, tents, water filters and generators.

U.S. President Joe Biden also said the United States would send money to relief organizations and coordinate with Libyan authorities and the United Nations to provide additional support.

Authorities transferred hundreds of bodies to morgues in nearby towns. More than 300, including 84 Egyptians, were brought to the morgue in the city of Tobruk, 169 kilometers (105 miles) east of Derna, the local Medical Center reported.

The victims’ lists reflected how Libya, despite its turmoil, was always a magnet for workers from around the region because of its oil industry.

More than 70 of Derna’s dead hailed from a single southern Egyptian village, el-Sharif. On Wednesday morning, hundreds attended a mass funeral in the village for 64 people.

Rabei Hanafy said his extended family lost 16 men in the flooding, 12 of whom were buried Wednesday. Another funeral for four others was held in a town in the northern Nile Delta.

Among those killed in Libya was the family of Saleh Sariyeh, a Palestinian originally from the Ein el-Hilweh refugee camp in Lebanon who had lived in Derna for decades. The 62-year-old, his wife and two daughters were all killed when their home in Derna was washed away, his nephew Mohammed Sariyeh said.

The four were buried in Derna. Because of ongoing gunbattles in Ein el-Hilweh, the family there could not hold a gathering to receive condolences from friends and neighbors, Mohammed said.

Derna, about 900 kilometers (560 miles) east of the capital, Tripoli, is controlled by the forces of powerful military commander Khalifa Hifter, who is allied with the eastern Libyan government. The rival government in western Libya, based in Tripoli, is allied with other armed groups.

Derna was once a hub for extremist groups in the years of chaos that followed the NATO-backed uprising that toppled and killed longtime dictator Moammar Gadhafi in 2011.

Magdy reported from Cairo. Associated Press Writer Bassem Mroue in Beirut contributed to this report.