Rescuers forced to halt efforts on Japan volcano

Last Updated Sep 29, 2014 10:59 AM EDT

Volcanic smoke was still spewing Monday from Japan's Mount Ontake. The volcano erupted without warning on Saturday, killing at least 36 people. Hundreds of hikers were covered with suffocating ash, toxic gases and falling rocks.

Rising levels of hazardous hydrogen sulfide gas made it too dangerous to continue rescue efforts on Monday, reports CBS News correspondent Seth Doane. They hope to resume work Tuesday wearing gas masks.

Before suspending the search, workers recovered more bodies and crews in helicopters hoisted people to safety, plucking them from a mountain that looked more like a moonscape.

"I'm so glad I came back alive," said one man who survived the eruption.

Another hiker captured the thick plume pushing over the mountain on Saturday. "This looks dangerous," he's heard saying in the video.

The once-blue sky quickly darkened as they were enveloped in a thick cloud.

"Get to the shelter," he yelled. "Cover your mouths!"

Pictures from inside shelters show ash billowing outside windows. Rocks landed with such force that they tore through rooftops.

Mount Ontake, Japan's second-highest volcano, has not seen a major eruption in 35 years. A popular hiking spot, it attracts up to 1,500 people every day this time of year. Tourists who came to enjoy beautiful weather and fall foliage say they had no warning.

Families were gathering Monday at a nearby town hall, awaiting word about those still missing.

"I think my loved one is still alive," one woman said. "Of course, I want to believe this."

There is no way to know how many more people may be on the mountain. Ash more than two feet thick in places is only complicating rescue efforts. Japan has more than 100 active volcanoes, but these were the first deaths from an eruption in Japan since 1991.