SEOUL - South Korean police Friday blamed shoddy construction for the collapse last week of a student-packed gymnasium that killed 10 people, and said they expected to file criminal charges.
The roof of the gym, at a resort complex near the southern city of Gyeongju, caved in under the weight of heavy snow on February 17 when about 560 college were attending a concert.
Ten people were killed and more than 120 injured.
Following an initial investigation, senior police investigator Bae Bong-Gil said evidence had been found of structural flaws and lax management controls.
Not enough bolts were used to hold together an auxiliary pillar and the roof, while some materials failed to meet government standards.
"Resort operators also did not remove snow from the roof," Bae said, adding the gymnasium was used as an auditorium without approval.
Police were continuing to gather evidence with a view to eventual criminal prosecution, he said.
The building was part of a sprawling mountain resort complex that had experienced unusually heavy snowfall in the preceding week.
It was a pre-engineered building, assembled with rigid frames and side walls - of a type normally used for warehouses and aviation hangars.
Some parents of the victims have accused the organisers of what was a student orientation event of failing to ensure the students' safety.
The resort owner, Kolon business group, has promised full compensation.
Gyeongju is a popular tourism spot for Korean and international travellers. Once the capital of the Silla kingdom, it boasts numerous historical sites and is located at the southern fringe of the Taebaek mountains.