Police in South Korea are investigating the death of four newborn babies, who died within 90 minutes of each other on the same intensive care ward in Seoul. The babies suffered from bloated stomachs and breathing difficulties before going into cardiac arrest, and passed away despite the best efforts of staff, who told police they did not know what caused the emergency. The other 12 babies in the ward have been discharged or sent to other hospitals while officers search the premises. Autopsies are expected to be carried out Monday.