Police officers, forensic scientists, architectural engineers and experts on safety facilities joined forces on Wednesday to secure evidence and identify the cause of the tragic ceiling cave-in that killed 10 people in Gyeongju, North Gyeongsang Province.

The ceiling of a prefab building at Mauna Ocean Resort crumbled on Monday evening, presumably under the weight of snow. There were 565 freshmen from Busan University of Foreign Studies attending a welcoming event in the building when it collapsed. Most got out soon after, but around 100 were caught in the wreckage. The accident killed nine students and one party organizer. Two were seriously injured and 101 others sustained minor injuries, according to the government.

The weight of the snow has been cited as a major cause for the collapse. But suspicions are mounting that the building was poorly built and that suitable construction materials were not used. Officials said the operator of the Manua Ocean Resort had not arranged any outside safety checks since the building was constructed six years ago.

“We will look into whether the gym was originally built as planned and whether the construction materials used were appropriate,” said Koh Jae-mo, an official at the National Forensic Service. “We are open to every possibility and will do a close examination if we find any kind of abnormal features during the investigation,” he added.

The gym used a metal pre-engineered building system that made it more vulnerable to heavy loads, experts said. Its rafters were very weak although buildings using the PEB structure require sturdy rafters since they have no pillars. The steel frames that are put between the panels on PEB buildings should have been thicker and stronger, they added. The combined weight of the snow that was piled up on the roof of the gym at the time of the accident is estimated at over 148 tons.

Herald Business, a local daily, reported that it was the resort operator who wanted to use sandwich panels for the roof, quoting an architect who designed and supervised the building’s construction. Choosing sandwich panels would have helped the operator save money on construction, the architect added. The resort is owned and operated by textile giant Kolon Group.

Officials also said that the gym had not had an official safety inspection by an outside organization since its completion. The operator is not obligated to carry out an outside safety inspection because of the building’s size. Only buildings that are 5,000 square meters or larger are required to have inspections. For smaller buildings, the owner of the facility is responsible for conducting inspections.

The police said they will also start summoning Kolon officials, witnesses and school authorities for questioning.

“For now we need to identify the cause of the collapse. After that, we will draw up an investigation plan and consider seeking charges against those responsible for the accident,” an official in the investigation team said.

Meanwhile, families of victims and Kolon Group have agreed on a compensation package so funeral arrangements can be made. The amount of the out-of-court settlement was not released.

“We have agreed to settle because we want to let our children go to a good place as soon as possible,” a victim’s family member was quoted as saying by Yonhap.

The government has also stepped up efforts to prevent a relapse. The Ministry of Security and Public Administration said it has launched a safety inspection into 62 public facilities in Gangwon Province, the country‘s eastern region that has been hit by heavy snow for weeks.

Buildings subjected for the inspection are those built with frames and side walls and are larger than 1,000 square meters, the ministry said. The government will also ban college student councils from holding orientations alone without support of the universities. Student council of the Busan University of Foreign Studies said it had organized the event alone with funds raised from participating students. The student organization has been at odds with the school.

By Cho Chung-un (christory@heraldcorp.com)