Jet-black smoke spews furiously from the volcano while screaming visitors frantically try to escape from an area near a ski lift house at Kusatsu Kokusai Ski Resort in Kusatsu, Gunma Prefecture, on Jan. 23. (Provided by a rescued woman)

KUSATSU, Gunma Prefecture--Survivors of the shock eruption at Mount Kusatsu-Shiranesan recalled the terrifying moments when thick smoke filled the sky and rocks rained down on skiers and snowboarders at a resort here Jan. 23.

One 60-year-old snowboarder was just about to descend the mountain from the area near the ski lift station at the summit of the ropeway at Kusatsu Kokusai Ski Resort when there was an unusual rumbling sound.

Within moments, jet-black smoke was rising and rocks, some measuring about 20 to 30 centimeters, were flying through the air. Suddenly, the area was plunged into darkness.

The man fortunately found a hollow in the snow which he quickly ducked into.

“I stayed there for a few minutes, but it felt like twice that,” said the man from Kawasaki, Kanagawa Prefecture. “I thought I was going to die.”

Rocks spewing out hit his left arm and his back, tearing his jacket.

Using his uninjured right arm, the man extended a hand to help Self-Defense Forces members who had been injured during training, one of whom had broken both legs and another who was hit in the head.

With his damaged snowboard still attached to his foot, he started to walk down the mountain unattended. He was carried to a hospital after reaching ground level safely.

“I’m deeply grateful that I am still alive,” said the man, who is familiar with the ski resort after frequent visits.

Masaru Suganuma, 73, was taken aback by a sudden loud explosive sound when he was relaxing with a cup of coffee in a restaurant at the summit.

Shortly after, volcanic rocks smashed through the ceiling of the restaurant.

Suganuma evacuated to the building’s basement. When he left the restaurant, he noticed that part of the ski slope was covered in volcanic ash.

Naoki Kaneko, 36, was aboard a ski lift heading to a slope in the mountain’s upper reaches from the ropeway summit station.

Kaneko, from Tokyo’s Edogawa Ward, was taking photographs of the stunning winter landscape with his smartphone when he saw black smoke billowing.

“Uh-oh, it must be an eruption” as he leaped to the snow-covered ski slope a meter away and took shelter in woods, from where he saw a volcanic rock the size of a soccer ball flying through the air soon after.

Kaneko’s wife Noriko, 43, thought she had no way out when the eruption flared as she was riding alone in a gondola. Black smoke spreading downwind shrouded the view surrounding the vehicle.

She heard rain-like sounds, and sandy debris seeped into the gondola through a crack in the window.

Kohei Sakurai, 33, who was visiting from Karuizawa, Nagano Prefecture, heard booming sounds twice from a gondola on the ropeway.

The desperate situation reminded him of the Japan’s deadliest postwar volcanic disaster in 2014 that 63 people dead or missing.

“I recalled footage of the eruption of Mount Ontakesan,” said Sakurai. “I thought I was going to die.”

He crouched and protected his head with his hands, praying for safety. Time seemed to pass by in slow motion.

Kana Sakurai, 28, was also trapped in a gondola.

“How can I survive?” she asked herself, gripped with fear.

After a while, the gondola started moving again, and Sakurai, from Naganohara, Gunma Prefecture, arrived safely at the ropeway summit station.