It happened at the Stony Brook North mobile home park Sunday around 8:00 a.m.
Firefighters told ABC11 the house is a total loss; it took 40 firefighters to put the fire out.
Officials say the fire caused heat damage to two other nearby homes.
Four people were displaced and three were taken to the hospital. Two children were treated for smoke inhalation and one adult was treated for burns to her arms.
The cause of the fire is still under investigation.