AMNA NAWAZ: Welcome to the "NewsHour."

We're following two major stories tonight.

The president's son Hunter Biden has been indicted by a special counsel on federal firearms charges.

We will have more on that in just a moment, but first to Libya, where deep fears are becoming horrific reality.

The death toll from devastating floods has spiked to more than 11,000, with thousands still missing, submerged in the muddy mire, or washed out to sea.

Stephanie Sy has that report.

STEPHANIE SY: From the sky, drone footage over Derna captures an apocalyptic scene, nearly a quarter of the city now a washed-out wasteland.

On the ground, the human toll is personal, the bodies of thousands of victims, some wrapped in plastic, others in blankets.

Without ceremony, they're loaded onto trucks and buried anonymously in mass graves.

It's been four days since the floods, and rescuers are still combing through swampy streets and searching the Mediterranean for survivors.

MOUSSA IBRAHIM, Libya Flood Survivor (through translator): It is a disaster that has gone beyond imagination.

We thought it was just floods, water going down.

But the mud is the greatest problem.

Bodies are buried under piles of mud and debris, three or four meters high of mud.

STEPHANIE SY: The driving rain was bad enough, but it was the failure of two dams upstream that doomed Derna, an unstoppable torrent barreling towards sleeping communities, sweeping everything and everyone in its path all the way out to the sea.

WALI EDDIN MOHAMED, Libya Flood Survivor (through translator): We woke up at around 3:00 or 3.30 in the morning.

We heard a large bang.

Anyone who was awake in Derna for sure must have heard it.

Anyone who was in the valley was swept away.

When we went outside, there was no more city.

It had been razed to the ground.

STEPHANIE SY: Officials say the dams had been neglected for more than 20 years, despite repeated warnings; $1.3 million allocated to fix the dams went unspent.

Now Derna's infrastructure is in ruins.

Five bridges collapsed, and nearly 20 miles of road crumbled, blocking access in and out of the port city.

MOHAMED ELJARH, Managing Partner, Libya Desk: Slowly, things are getting organized, but it has been chaotic, and it is the fourth day.

STEPHANIE SY: Mohamed Eljarh is an expert on Libyan affairs.

You are in Al Bayda, just outside of Derna, the worst-hit area.

What do things look like on the ground right now?

MOHAMED ELJARH: The situation remains difficult on the front of finding bodies, getting them out, and then carrying out the identification process and then the burial process of it.

And then you have the people who survive.

It's a struggle to try and organize and coordinate aid to ensure that people have drinking water -- there's no drinking water in the city of Derna -- that people have the necessities of food.

STEPHANIE SY: More than a decade of political conflict contributed to the disaster.

After the U.S.-backed overthrow of dictator Moammar Gadhafi in 2011, rival factions divided the country and left cities like Derna governed by militia groups.

MOHAMED ELJARH: The failure started with not having a post-intervention strategy by the international community to ensure that there was a proper transition to functional governance in Libya.

And then there was a failure of Libyan transitional governments and leaders to meet the aspirations of the people.

So there is no doubt that we could have avoided, I mean, the magnitude of loss of life, of injuries, of displaced, the suffering.

STEPHANIE SY: Casualties also continue to mount in Morocco.

Aftershocks persist nearly a week after a 6.8 magnitude quake struck the Atlas Mountains just south of Marrakesh.

The threat of tremors makes urban areas too dangerous for displaced people to relocate.

But remote regions are no better.

Bodies are decaying underneath untouched piles of rubble.

And homeless families say makeshift tents aren't enough to shield them from the elements.

JMIA JALJAL, Moroccan Earthquake Survivor (through translator): We want to transfer people to Marrakesh.

If they stay here under the tents, they will suffer a lot because they are in a mountain.

We don't need help in food.

People don't die of hunger, but they can die because of the snow and cold.

STEPHANIE SY: Two North African nations grappling with extreme natural events and their own extreme losses.

MOHAMED ELJARH: You can feel the trauma across Libya.

Everyone, they feel a responsibility that they need to help, they need to do something.

So it's a trauma for the whole country.

STEPHANIE SY: For the "PBS NewsHour," I'm Stephanie Sy.