RAISIN TOWNSHIP, Mich. (AP) — Authorities say two boys from Ohio have died following a weekend fire at a cabin in southern Michigan.

The Daily Telegram of Adrian reports that the boys, ages 9 and 15, were from the Dayton area and were visiting with their grandparents and great-grandparents.

The boys’ names weren’t immediately released. The newspaper says the boys were in one cabin in Lenawee County’s Raisin Township, about 55 miles southwest of Detroit, while the adults were sleeping in another cabin at the time of the fire.

Rescuers responded around 1 a.m. Sunday after one of the adults heard what sounded like an explosion and saw flames.

Raisin Township Fire Chief Jim Hannah says the cause of the fire is under investigation, but it has been determined that it isn’t suspicious.