A global aid effort for Libya gathered pace Thursday after a tsunami-sized flash flood killed at least 4,000 people, with thousands more missing — a death toll the UN blamed in part on the legacy of years of war and chaos.
The enormous surge of storm water burst two upstream river dams late Sunday and reduced the city of Derna to an apocalyptic wasteland where entire city blocks and untold numbers of people were washed into the Mediterranean.
The UN World Meteorological Organization (WMO) said most of the deaths could have been avoided if early warning and emergency management systems had functioned properly in the war-scarred country.
With better coordination, "they could have issued the warnings and the emergency management forces would have been able to carry out the evacuation of the people, and we could have avoided most of the human casualties," said its chief Petteri Taalas.
Hundreds of body bags now line Derna's mud-caked streets, awaiting mass burials, as traumatised and grieving residents search mangled buildings for missing loved ones and bulldozers clear streets of debris and mountains of sand.
The UN, United States, European Union and multiple Middle Eastern and North African nations have pledged to send rescue teams and aid including food, water tanks, emergency shelters, medical supplies and more body bags.
The floods were caused by hurricane-strength Storm Daniel, compounded by poor infrastructure in Libya, which descended into years of turmoil after a NATO-backed uprising in 2011 toppled and killed longtime dictator Moamer Kadhafi.
Libya is now divided between two rival blocs -- the UN-backed, internationally recognised government in Tripoli, and an administration based in the disaster-hit east.
Access to Derna in the east remains severely hampered as roads and bridges have been destroyed and power and phone lines cut to wide areas, where at least 30,000 people are now homeless.
The catastrophe's true death toll remained unknown, and officials have provided conflicting numbers.
A total of 3,840 bodies had been recovered by Wednesday, said Lieutenant Tarek al-Kharraz, spokesman for the interior ministry of the administration ruling eastern Libya.
But many more people may have been washed out to sea or buried in the sand by the wall of muddy water that tore through the city overnight from Sunday to Monday, peaking as high as the second storey of buildings.
The International Federation of Red Cross and Red Crescent Societies has warned that 10,000 people are missing.
One man in the city recounted how the rains lashed the area from early evening, before the massive flood surge hit after midnight: "At around 2:00 am I was at home on the third floor when the floodwaters began to wash away the cars in the street".
Aid has been sent or promised by numerous regional nations including Algeria, Egypt, Jordan, Kuwait, Qatar, Tunisia, Turkey and the United Arab Emirates as well as the Palestinians.
Among the first aircraft to arrive in Benghazi, a 300-kilometre (180 mile) drive from Derna, have been eight Emirati planes carrying rescue teams, hundreds of tonnes of relief goods and medical aid.
The United States has also pledged to help, and in Europe the aid effort has been joined by Britain, Finland, France, Germany, Italy and Romania.
Climate experts have linked the disaster to the impacts of a heating planet combined with Libya's decaying infrastructure.
Storm Daniel gathered strength during an unusually hot summer and earlier lashed Turkey, Bulgaria and Greece, flooding vast areas and killing at least 27 people.
"Storm Daniel is yet another lethal reminder of the catastrophic impact that a changing climate can have on our world," said UN High Commissioner for Human Rights Volker Turk.
Turk called on all sides in Libya "to overcome political deadlocks and divisions and to act collectively in ensuring access to relief.
"This is a time for unity of purpose: all those affected must receive support, without regard for any affiliations."
The WMO's Taalas told reporters in Geneva that Libya's years-long conflict meant its meteorological "observing network has been very much destroyed, the IT systems have been destroyed", he said.
"The flooding events came and there was no evacuation taking place, because there was not the proper early warning systems in place."
If evacuations had taken place, the human toll would have been far lower, he said.
"Of course we cannot fully avoid economic losses, but we could have also minimised those losses by having proper services in place," he said.
In the aid effort since the floods hit, the Tripoli-based government has declared a national emergency and deployed aircraft, rescue crews and trucks filled with aid.
The need is huge, with at least 30,000 people made homeless in Derna and eastern areas, where other towns and villages were also hit by floods and mudslides, according to UN agencies.
In an additional threat, landmines left over from the war may have been shifted by the floods, warned Erik Tollefsen, head of the weapon contamination unit at the International Committee of the Red Cross.