Hanwha Aerospace CEO Son Jae-il (center) arrives Friday at a joint memorial altar set up at the Yuseong-gu District Office in Daejeon to pay respects to the victims of a deadly explosion at the defense firm’s Daejeon plant on June 1, which left five people dead and two injured. (Yonhap) Hanwha Aerospace CEO Son Jae-il has been booked over a June 1 explosion at the defense firm’s Daejeon plant that killed five people and injured two, labor authorities said Monday.The Daejeon Police Agency said Monday that it had booked Ga Jae-woong, head of Hanwha Aerospace’s Daejeon facility, on charges of professional negligence resulting in death and injury.The Daejeon Regional Employment and Labor Office also said Monday that it had booked Son and Ga for alleged violations of the Serious Accidents Punishment Act and the Occupational Safety and Health Act, respectively.Son and Ga are accused of failing to properly manage safety at the company’s facility in Yuseong-gu, Daejeon, leading to the fatal explosion.Son, Ga, and a third unnamed Hanwha Aerospace official have also had travel bans imposed on them by police.A dedicated investigation team was formed shortly after the accident, which occurred at around 10:59 a.m. in the cleaning room of the company’s Daejeon plant. It has since questioned seven company officials as well as bereaved family members.Police and labor authorities also raided Hanwha Aerospace’s headquarters in Seoul, its Daejeon plant and its Daejeon R&D campus on June 4 to determine the accident’s cause.During the raids, investigators seized some 5,400 items, including six mobile phones belonging to executives and employees as well as various documents, and are currently analyzing them.“Travel bans have been imposed on two people booked in connection with the case and one witness as we continue the investigation,” a police official said.“We will clearly determine the cause of the accident and where responsibility lies through an analysis of the materials secured during the raids and questioning of those involved.”