It started with a large vehicle that got stuck in the deepening snow. That minor incident grew into a monster snow-covered traffic jam as more than 1,000 cars became stranded on a highway that runs between Tokyo and the city of Niigata along the Sea of Japan coast.
The snarl began Wednesday night, local news sources reported.
"The snow was extremely heavy," one driver told the public broadcaster NHK. "As time went by, the cars got buried. I was really scared. I've eaten all of my food and drinks. Now, to drink water, I have to melt snow I collect in a plastic bottle."
Heavy snowfall in recent days, especially in the Niigata and Gunma prefectures, blanketed some areas with more than 6 feet of snow. NHK reported that these prefectures have seen seven times more snow than they typically do at this point at this time of year.
"I hardly slept, and I was worried because I had absolutely no information (about the situation)," a 48-year-old man, who had been driving to his home near Tokyo, told Kyodo News.
The line of cars at one point stretched more than 10 miles, authorities told the news agency.
For a time, traffic was stopped in both directions. Lanes bound for Niigata were cleared by Friday morning, while about 260 vehicles on the Tokyo-bound lanes were still stuck as of 7 p.m. local time Friday, Kyodo reported.
The East Nippon Expressway Co. said it could be Saturday before all the cars are cleared.
"I would like to apologize for the extensive period of closure along the Kan-etsu Expressway caused by snow, and particularly for trapping our customers for a long period of time," company President Toru Obata said at a press conference, NBC News reported.
Japan's Self-Defense Forces distributed food, water, blankets and fuel to those stranded in their cars, and worked with shovels to budge the vehicles.
Two people were taken to the hospital for respiratory problems and nausea on Thursday, CNN reported.
"The government will do its utmost to rescue anyone who is stuck in their vehicle," said the government's top spokesman, Chief Cabinet Secretary Katsunobu Kato, according to Reuters, which reported the snow has knocked out power to more than 10,000 households.
Meanwhile, more heavy snow is forecast for the weekend.