Spontaneous combusion in a pile of mulch is being blamed for a massive fire in Sussex County that destroyed one house and damaged two others.

Millville firefighters encountered heavy fire on the exterior of the house in the Ocean Vew community.

As residents were leaving, they said they noticed a fire in a mulch pile had spread to a tree, WBOC reported.

Delaware fire marshals determined the fire was accidential.

There were no injuries.