On Wednesday evening, an ambulance was called to an address in Jönköping due to a cardiac arrest.
An adult and a child under one year had had an accident in an apartment, according to the alarm to SOS.
The child was taken by ambulance to hospital but his life could not be saved, the police write on their website. There is no indication that the adult was injured.
The incident is being investigated as causing another person’s death and the adult has been arrested.
Relatives have been notified of the death, the police write.