FORT LORAMIE, Ohio -- A family reunion at Lake Loramie State Park in Shelby County took a tragic turn when fire broke out in a camper Friday morning.

Authorities said four people were injured and rushed to local hospitals, including a 3-month-old baby. The baby, Jordan Flora, is in fair condition at Children's Medical Center.

The baby's grandparents, Steven and Karen Blocher, are in critical condition at Miami Valley Hospital. The baby's father was treated for smoke inhalation and released.

Witnesses reported hearing an explosion, then seeing the victims covered in flames.

State and local fire investigators are still trying to determine how this happened.