South Korean police say a hospital fire that killed 37 people in the southern city of Miryang was most likely caused by an electrical fault in the first-floor emergency room.

A police official said Saturday that a joint investigation carried out by police, fire services and forensic experts concluded that a fault in the electrical system in the ceiling of the emergency room's pantry most likely sparked Friday's blaze.

Also Saturday, South Korean President Moon Jae-in visited the site of the country's deadliest blaze in a decade and vowed to raise safety standards for hospitals. He also met with the victims' grieving relatives.

Officials say the six-floor facility did not have sprinklers because it wasn't big enough to be required by law to have such systems.