The Jacksonville Fire and Rescue Department said a propane tank exploded outside a Southside home on Wednesday.
Three children, ages 17, 6 and 1, were in the home at 7645 Praver Drive East at the time of the explosion but managed to get out safely.
"I don't know if it was a freak accident or... I really don't know," said Mark Satt, the children's stepfather. "I'm so thankful the little ones — that's the most important thing is they made it out. ... As long as we're all together, that's all that counts."
Fire badly damaged the home, JFRD said, but it's unclear if the explosion started the fire or was caused by the fire.
"We've lost everything," Satt said. "Everybody that works (in the family), they have menial jobs... just enough to make ends meet, and now we've lost everything."
The American Red Cross is assisting the family.
District Chief Roger Lewis said the state fire marshal will be assisting in the investigation of what happened, but so far investigators believe the fire was accidental.
"It looks like the fire originated at the rear of the house and somewhere along the process of the fire it looks like we had an explosion of what appears to be a 20-pound cylinder to a gas grill," Lewis said. "We've got pretty extensive damage at the rear of the house.
"We don't really know exactly whether or not the grill was actually part of the ignition source or whether or not it was just an exposure to a fire that already existed," he said. "Either way, a 20-pound cylinder is subject to explode when it gets hot enough."
The family has set up a VyStar account for donations under the name Mark Satt. The account number is 7504762593. Donations can be made online with routing number 263079276.