"This case occurred because the managers and supervisors (of the hospital) have irresponsibly overlooked the long-standing, unlawful practice," a police official said. "Such a case should not be repeated again."  

On Dec. 16, the four infants died in less than a two-hour period while being treated in the intensive care unit of the hospital. Forensic results later confirmed that their deaths were all caused by the same type of bacteria that can be fatal to immunocompromised patients.

Of the seven, two doctors and one nurse were put under arrest Wednesday after a Seoul court issued warrants for them, while arrest warrants were not sought against two other doctors and two other nurses. (Yonhap)