South Korea's President Park Geun-Hye has called for a full investigation into the collapse of an auditorium near the city of Gyeongju that killed at least 10 and injured more than 100.
Emergency staff worked through the night to find survivors.
More than 560 college students were believed to be attending a concert when part of the auditorium caved in.
Nine of those killed in the disaster - blamed on the weight of snow on the roof - were students.
The weather is also thought to have slowed down rescue efforts.
"It is heart-rending that so many lives were sacrificed... a thorough investigation must be carried out," Mrs Park told a cabinet meeting.
Officials say all the students are now believed to be accounted for.
A large number of students from the Busan University of Foreign Studies had gathered at the auditorium of the Mauna Ocean mountain resort for a welcoming ceremony on Monday night during an orientation event for first-year university students.
"We assume that the centre of the building was unable to withstand the weight of the snow, so it collapsed," firefighter Kim In-yoo said.
A spokesman for the Ministry of Security and Public Administration told reporters: "Ten people are confirmed dead, two were seriously injured and 101 others suffered bruises and cuts."
Rescuers continued searching the wreckage on Tuesday to check for anyone trapped inside, the AFP news agency reported.
Local media reports say the collapse happened at around 21:15 local time (12:15 GMT) on Monday.
Many students managed to get out of the damaged building by themselves.
"The ceiling came crashing down at the front near the stage," one student told South Korea's YTN news channel. "Then pandemonium broke out and everyone started rushing towards the exits, shouting and screaming," he added.
The building was a modern, pre-fabricated structure, and local police have reportedly asked why the snow was not cleared from the roof before the party began.
Gyeongju is a southern historic city that served as the capital of one of the Korean peninsula's ancient kingdoms, and is a popular tourist destination.
One of the world's worst peacetime building collapses happened in South Korea in June 1995, when Seoul's Sampoong Department Store collapsed, killing hundreds.