Six children died when candles used to light a mobile home which had no electricity started a fire, authorities in the Mississippi town of Tchula said.
The four-month-old daughter of the home's owner was seriously ill in hospital, a spokesman said.
No adults were home when firefighters were called to the blaze yesterday morning, said Holmes County Sheriff Mr Willie March said.
Three victims and the surviving baby were the children of Ms Angela Williams. The other three victims were her sister's children, who were spending the night.
Tchula Fire Chief Mr Sharkey Ford said that when he arrived at the scene volunteers were handing the children down a line from the trailer.
"We were looking for ones that had signs of life and trying to resuscitate them," he said. "Not in the 30 years I've been here have we had anything as tragic as this."
AP