Eight children were among the dead, Coronel's deputy mayor, Javier Valencia said.
He added that the fire's cause was unknown but that officials were investigating whether a heating unit had overheated.
Three families were living in two homes destroyed by the fire.
Mr Valencia criticised an apparent recent increase in construction of housing on unauthorised land, known in Chile as "encampments", where forest fires are known to occur.
Coronel, close to Concepcion, a major city in southern Chile, is an area heavily affected by such fires, due to the high temperatures brought about by the southern hemisphere summer.
Tens of thousands of Venezuelans escaping poverty and violence at home are risking their lives to travel south to Chile, one of the wealthiest countries in South America.
Many migrants cross the border by walking from Bolivia or Peru, often in extremely dangerous conditions.