A fire broke out in a Mount Vernon building Thursday when a woman attempted to keep herself warm in the suddenly cold weather.Four families are displaced after flames ripped through the apartment building at 193 West Lincoln Avenue. Residents say the fire was sparked when a woman lit her oven, trying to keep warm. Tenants say the building was without heat and that is why the woman attempted to use her oven to keep warm. The building manager, Ricardo Zamudio, maintains the city shut off the gas.The fire chief says the families won't be allowed back into their apartments until the building department inspects which floors, if any, are safe to occupy. In the meantime, the American Red Cross is providing housing for all 20 displaced residents. The woman who accidentally started the fire has been hospitalized.