WALDORF, Md. (AP) — A fire ripped through a house in Charles County, Maryland, on Sunday, killing four children and two adults, authorities said.

One person managed to escape the blaze reported around 8:40 a.m. at the home in Waldorf, about 55 miles (88 kilometers) south of Baltimore, WTOP-TV reported.

It took about 70 firefighters more than an hour to control the flames. One firefighter was hospitalized and another first responder was treated at the scene for unspecified injuries.

The cause of the fire was under investigation. Master Deputy State Fire Marshal Oliver Alkire said the blaze originated on the right side of the home within an enclosed porch.

The ages and names of the victims were not released as of Sunday evening.

Alkire said officials didn’t immediately know if the residence had working smoke alarms.