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

Around 8:40 a.m., a fire broke out at a house in Waldorf, approximately 55 miles (88 kilometers) south of Baltimore, as reported by WTOP-TV. One individual managed to flee from the flames.

Over 70 firefighters worked for more than an hour to put out the fire. A firefighter was taken to the hospital, and another responder received treatment at the scene for injuries that weren’t specified.

The reason behind the fire is still being examined. Master Deputy State Fire Marshal Oliver Alkire noted that the fire started on the home’s right side in 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.