The massive flames broke out along Briarcliff Drive in the Overview Gardens neighborhood of Minquadale at 3 a.m. Tuesday.
Fire officials say the fire was already shooting through the roof by the time crews arrived.
The flames were so intense, they began melting the siding off of homes next door.
A New Castle County Police Officer and a firefighter pulled one resident to safety.
Medics took him to Christiana Hospital, where he was listed in stable condition late Tuesday morning.
The Red Cross is helping three other adults and one child who lived in the house.
State fire investigators are conducting an investigation into the cause and origin of the fire.
