PowerPoint Show by Andrew

Nepalis started fleeing their devastated capital of Kathmandu on April 27 after Saturday's earthquake killed more than 3,700 people and toppled entire city blocks.

The United Nations has launched a massive aid operation, but severed communications and landslides in the Himalayan nation pose formidable challenges. Residents of Kathmandu are in need of almost everything - shelter, fuel, food, medicine, power, news, workers, and more.

People are searching for lost loved ones, sorting through rubble for their belongings, and struggling to meet their families' needs. The earthquake was the worst to hit the South Asian nation in over 80 years, strong enough to be felt across parts of India, Bangladesh, Tibet, and Pakistan.

A Nepalese man cries as he walks through the earthquake debris in Bhaktapur, near Kathmandu, Nepal, on April 26, 2015.

An aerial view of hillside residential buildings damaged by Saturday’s earthquake at Trishuli Bazar in Nepal, on April 27.

The shadow of an Indian Air Force aircraft carrying relief material is cast on an area where tents are setup by residents in Kathmandu on April 27.

Rescue workers remove debris as they search for victims of earthquake in Bhaktapur near Kathmandu, on April 26.

Nepalese residents walk past road damage following an earthquake in Kathmandu on April 26.

People gather on an open space for security reasons at the Basantapur Durbar Square, damaged in Saturday’s earthquake in Kathmandu,on April 26.

Nepalese police personnel and volunteers clear the rubble while looking for survivors at the compound of a collapsed temple in Kathmandu on April 27.

Nepalese rescue personnel help a trapped earthquake survivor, as his friend lies dead next to him in Swyambhu, in Kathmandu on April 26.

Residents line up for food in an evacuation area set up by the authorities in Tundhikel park on April 27, 2015 in Kathmandu.

Residents line up for food in an evacuation area set up by the authorities in Tundhikel park on April 27, 2015.

Nepalese army personnel and a sniffer dog search for victims amid the rubble after Saturday's earthquake in Bhaktapur, Nepal, on April 27.

Victims of Saturday's earthquake lie inside helicopter as they are evacuated from Trishuli Bazar to the airport in Kathmandu on April 27.

Quake-damaged buildings in Kathmandu, Nepal, on April 27.

A man carries an injured child, after Indian Army soldiers evacuated them from Trishuli Bazar to the airport in Kathmandu on April 27.

People look at the debris of an ancient temple after it was damaged in Saturday’s earthquake, in Kathmandu, on April 26.

A cloud of snow and debris triggered by an earthquake flies towards Everest Base Camp, moments ahead of flattening part of the camp in the Himalayas.

A rescue chopper prepares to land, carrying people from higher camps to Everest Base Camp, Nepal, Monday, April 27, 2015.

Rescue team personnel carry an injured person towards a waiting rescue helicopter at Everest Base Camp on April 26.

A rescue team member sits on top of the debris of a collapsed temple at Basantapur Durbar Square on April 27.

Nepalese rescue personnel observe damaged buildings following the earthquake in Kathmandu on April 26, 2015.

The body of a victim lays underneath debris from one of the collapsed buildings on April 26, 2015 in Bhaktapur, Nepal.

A man pedals a Nepalese cycle rickshaw past damaged buildings at the Basantapur Durbar Square in Kathmandu.

A Nepalese man performs rituals during the cremation of his mother who died in the earthquake in Bhaktapur, near Kathmandu, on April 26.

Victims of Saturday's earthquake are cremated along a river in Kathmandu on April 27, 2015.

People burn the bodies of earthquake victims at a mass cremation at Pashupatinath in Kathmandu on April 26, 2015.

A woman mourns her granddaughter, who died in Saturday's earthquake.

Residents look at collapsed houses in Bhaktapur, on the outskirts of Kathmandu, on April 27.

People sleep as they wait outside the departure terminal at the airport in Kathmandu.

A woman receives medical treatment at Dhading hospital, in the aftermath of Saturday's earthquake, in Dhading Besi, Nepal.

Nepalese people make themselves warm while they stay on open ground in fear of further aftershocks in Kathmandu, Nepal, on April 27, 2015.