For over 300,000 years, Mount Ontake in Nagano, Japan was thought to be inactive, until 1979 when the 3063 meter volcano erupted, causing ashfall in cities 93 miles away. On Saturday September 27, 2014, the volcano erupted again, causing the country’s deadliest volcanic eruption in 90 years.

Mount Ontake is the second largest volcano in Japan and a popular tourist destination for hikers. Without any earthquakes or signs of disturbance on the mountain, it was covered with hikers at 11:52 a.m. when the volcano erupted.

“The best season for the leaves to change just started, the weather was beautiful, it was the weekend, and it was lunchtime,” Nagano tourism official, Masahito Ono said in an interview with The Weather Channel.

Initially, it was believed that most hikers had evacuated the mountain before any damage could be done, but by the end of the day, 34 people were reported injured and 32 were reported missing. After over two weeks of searching through the layers of the ash-covered rubble on the mountain, there is a confirmed death toll of 55, and rescue teams are still looking for bodies.

“It was like thunder,” a lodge owner near the summit said to Japanese broadcaster NHK. “I heard ‘boom, boom’, then everything went dark. There were six inches of ash on the ground.”

While there are still nine people missing, the search for more bodies was temporarily stopped on October 5 due to the approach of Typhoon Phanfone. The typhoon threatened to sweep over Mount Ontake, possibly creating a massive land slide and taking remaining bodies with it. No progress in the search for bodies was made until October 11, when they began to use a strategy in which rescuers spread out in a line and swept the rubble.

“We made a lot of preparations and gathered a lot of information, but we didn’t imagine the mud would be this bad,” vice chief of MPD’s riot police squad said in an interview with National Post. “It’s like concrete or mortar beginning to solidify.”