GYEONGJU, North Gyeongsang Province (Yonhap) ― Police on Friday blamed shoddy construction and poor materials for last week‘s deadly gymnasium collapse that killed 10 people, mostly college students, and injured 128 others.

The roof of the gymnasium at the Mauna Ocean Resort in Gyeongju, North Gyeongsang Province, caved in on some 560 incoming freshmen of the Busan University of Foreign Studies on Feb. 17 during a welcoming party.

Announcing the interim results of their investigation into the tragedy, officers at the Gyeongju Police Station said that the collapse was the result of overall poor construction and lax management of the building.

“The gymnasium showed numerous problems in terms of design, construction and supervision,” Bae Bong-gil, a lead investigator into the case, told a press briefing.

After holding a joint on-site inspection with structural engineers and studying an architectural blueprint of the building for the past two weeks, police said they also obtained evidence suggesting structural flaws.

Not enough bolts were used to hold together an auxiliary pillar and the roof, officers said, adding that some materials of a main pillar did not meet government standards.

“Also, resort operators did not properly remove snow from the roof,” Baek said, noting that heavy snow that had piled up on the roof caused the collapse.

Hit by a severe winter storm, the Gyeongju area received more than 50 centimeters of snowfall in the preceding week, the officers added.

“We plan to seek criminal charges against those responsible for the safety inspection of the resort and building the gymnasium, as well as contractors of the substandard materials,” Bae said, without giving further details on the identity of those involved.