A fire in a South Memphis neighborhood killed four children Wednesday afternoon, and police detained their father, authorities said.

The blaze erupted shortly before 3 p.m. at a two-story apartment building in the Washington Heights area. It took around 50 firefighters about a half-hour to control the fire, the Memphis Fire Department tweeted.

Four children, including a 6-year-old, a 2-year-old and two 4-year-olds, were found inside a back bedroom during rescue operations, according to the Fire Department.

WREG-TV reported that the children's grandfather said the children, two boys and two girls, were at home with their father while their mother ran an errand.

Memphis police said they detained the father, but his name and other details weren't immediately released.

The cause of the fire remains under investigation.