KATHMANDU — Nepal observed a national day of mourning Monday following a glacial and mountain collapse near the China-Nepal border on Aug. 26 that killed at least 1,398 people. More than 5,500 individuals remain missing, including approximately 800 foreigners.

Flags flew at half-mast across the nation, and candlelight vigils were planned for later in the day, aligning with traditional Hindu mourning rituals observed on the 13th day after a death. The disaster swept away entire communities, destroyed roads and demolished homes.

Hundreds of hydropower workers are among those missing, many feared trapped deep inside tunnels. Rescue teams extracted three of these workers alive — two Nepalis on Friday and a Chinese man on Saturday.

Nepal Army spokesman Raja Ram Basnet confirmed Monday that rescue operations were continuing with full intensity. "Our focus is on search and rescue at three levels — on ground, by air, and in the tunnels," Basnet said. "We are making sure that no one is still stranded."

Families of the missing workers, gathered in Kathmandu, called for faster government action. Reena Amatya Shrestha, whose brother is among the missing, expressed frustration with the pace of rescues. "We have a lot of hope," Shrestha said. "They say they are doing rescue. If the rescue is there, where's the result? We need the result."

Australian tunnel rescue expert Arnold Dix is advising Nepali teams on the complex operation. Dix, president of the International Tunnelling and Underground Space Association, described the situation as demanding. "Not one rescue, but multiple potential rescues, unfolding at the same time, in different places, each with its own dangers, uncertainties, and lives that may still be saved," he said.

Dix advised the team during the 2023 Indian rescue of 41 men trapped for 17 days in the collapsed Silkyara tunnel in Uttarakhand state. "We are measured not only by the lives we save, but by the lives we refuse to abandon," he said. "Silkyara taught me never to confuse unlikely with impossible."

Experts from China, India and South Korea are assisting Nepali teams in the rescue operation.

With mortuaries overflowing, Nepali police confirmed that hundreds of bodies have been buried in mass graves after DNA samples were collected for future identification. Only about 100 bodies have been identified and returned to their families.

The precise cause of the glacial collapse remains unclear. Climate change is accelerating glacial melting globally, which increases the risk of such disasters. Nepal, a largely rural nation of 30 million people, has contributed minimally to the greenhouse gas emissions that drive global warming.

Nepal's government estimates that reconstruction efforts could cost billions of dollars, a significant burden for an economy already under pressure. The current government now faces the substantial task of rebuilding devastated communities and critical infrastructure across the affected regions.