1. The judgment of the court of first instance, including the Plaintiff’s claim against the Defendants expanded in the trial room, is as follows.

1. Basic facts

A. The Plaintiff is one of the parties’ status 1) The Plaintiff is a company operating racing H hotel and I set. The J is the Plaintiff’s head of HnR, K is the Plaintiff’s head of HnR, K is the overall manager of K I set, L is the manager of the facility management office, and L is the Defendant G is the actual operator of the Defendant B Co., Ltd. (hereinafter “Defendant B”), who is in charge of construction, such as the manufacture and installation of steel-frame structure of the sports center in I set (hereinafter “instant sports center”). Defendant C is the manager of the business division, Defendant D is the head of the material division, Defendant E is the head of the production division, and Defendant F is the head of the factory.

B. The instant sports hall collapse accident 1) The size of the instant sports hall and the instant sports hall in the construction method is a gymnasium located in AY at Sejong-si, and the building ordered by the Plaintiff (MM Co., Ltd.). The instant sports hall is a gymnasium newly built with the structure of the steel-frame sand site panel (10 meters in central height, 8 meters in height, 31.2 meters in width, 36.6 meters in length, and 36.6 meters in length) on the site from 4,029 square meters up to 4,029 square meters. Accordingly, the Plaintiff planned to newly construct a gymnasium for the purpose of improving the early profit structure of the gymnasium and planned to attract considerable number of people, such as Taekwondo campaigns, to a new construction of a gymnasium as an ancillary facility in the gymnas structure and to a relatively short construction period in the gymnas structure and construction method.