iStock/Thinkstock(BALTIMORE) — Six children are missing, and three other children and their mother are in the hospital, after a fire tore through a home in Baltimore, Maryland, early Thursday morning, officials said.

The blaze started at the three-story home in northeast Baltimore just after midnight, Roman Clark of the Baltimore City Fire Department told ABC News.

Three children and their mother escaped the blaze; the mother and two of the children were hospitalized in critical condition and the third child was hospitalized in serious condition, Clark said.

Six other children are missing. The home’s third floor collapsed into the second floor, making the search difficult, Clark said.

The ages of the missing and hospitalized children range from 8 months to 11, Clark said.

Authorities did not identify the woman, but Maryland Rep. Elijah Cummings said the fire involved one of his staff members, Katie Malone, “and her young family.”

“I am asking that our entire community pray for my staff member, Katie Malone, and her young family. Katie has worked as a Special Assistant in my Catonsville office for nearly 11 years where she dutifully serves my constituents in the areas of immigration, postal services, and the military, including Service Academy nominations,” Cummings said in a statement. “My staff is a family and this unimaginable tragedy is shocking and heartbreaking to us all.”

Authorities said the rescued woman is believed to be the mother of all nine children.

The rescue operation is ongoing; an excavator is at the scene to remove some of the heavy debris so crews can more easily search for the missing children, Clark said.

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