The accident occurred on Highway 56 in Bie outside Katrineholm at around 3 p.m. on Sunday, writes Katrineholms-Kuriren.
One person was seriously injured and had to be taken to hospital by ambulance helicopter. Three more people were taken to hospital with minor injuries, while a fifth person escaped unharmed.
Later in the evening, Mälar Hospital announced that the seriously injured man had died.
