Hundreds of trekkers were on the popular Annapurna Circuit in the Mustang area of Nepal when disaster struck last week. At least 39 trekkers and their Nepalese guides died in avalanches and from exposure, many of them trying to get down, unable to see the trail in freezing whiteout conditions. Many others who survived suffered severe frostbite and have had or soon will undergo amputations.

One guide, Munchang Lama, told a Nepali journalist that he was pitching a tent for his two Israeli women clients when, “Suddenly it started raining and I took shelter between two rocks. Next morning I was not able to walk because my leg was stuck in snow.” He stayed alive by eating nuts, chocolate and a banana he found in the women’s bags until he was rescued 48 hours later, but he did not know what became of his clients.

Horst Ulrich, a 72-year-old German on a trek with a group of friends, watched four Nepali guides swept away by an avalanche.

“We were in a dangerous spot and shocked by the conditions we were seeing unfold in front of our eyes. We just got lucky.”

In addition to the casualties among the trekkers, several Nepali yak herders and locals traveling between villages to attend festivals, as well as two Slovaks and three Nepali guides preparing to climb nearby 26,795-foot high Dhauligiri were killed.

It didn’t need to happen.

The storm that dumped six feet of snow on the mountains in three days was triggered by Cyclone Hudhud, a Category 4 hurricane in the Bay of Bengal with a track crossing the Annapurna area predicted by several weather services. The storm that trapped and killed the trekkers was neither a freak nor unexpected, despite being labeled such by several media outlets, including the New York Times. Such powerful storms are not unusual in the Himalaya, even in the fall trekking season when long periods of stable and clear weather are common. “I had several clients doing climbs,” said Michael Fagin, meteorologist and lead forecaster at EverestWeather.com, “and I notified them a week to 10 days ago. People are saying that the storm was unusual, but it’s not out of the ordinary.”

The storm precipitated perhaps the worst mountain disaster in Nepal’s history, at least for the booming tourism industry that accounts of 4 percent of the GNP of one of the world’s poorest nations. Approximately 96,000 trekkers visit Nepal each year to view and walk amidst its spectacular mountains.

Most of the young trekkers traversing the circuit still find time to check their email and update their Facebook pages. That so many of them blundered into a Category 4 hurricane—spawned blizzard means that either the information didn’t reach them or nobody heeded the warnings. Unlike this spring’s Everest avalanche that killed 16 Sherpas, this was a major meteorological event with plenty of lead-time.

Rupam Jain Nair and Gopal Sharma of Reuters report that “the government has admitted failing to issue any warning that the weather would take a sudden turn for the worse, and has promised to set up an early-warning system.”

For 39 people, it’s too late.