'Tragedy': 3 children die in house fire while mom, 2 siblings escape alive

Three young children have died in a house fire in Indiana while their mother and two other siblings managed to escape the blaze alive, according to officials.

The victims were 11-year-old Danielle Plock Sims, 6-year-old Thomas Plock Sims and 3-year-old Roseanna Plock Sims, according to a news release from the state's Department of Homeland Security.

The fire in Tell City, along the Indiana-Kentucky border, was reported shortly after 3 a.m. Friday, according to Casey Kenworthy, spokesman for the Indiana Department of Homeland Security.

The mother, who tried, but was unable to reach her children, was hospitalized in fair condition, officials said at a news conference.

A 13-year-old boy escaped the home through a second-story window suffering non-life-threatening injuries, officials said.

Another child called 911 and also tried to reach her siblings, authorities said. She was hospitalized, authorities said.

It appears the family was asleep when the blaze ignited, officials said.

Responders found flames shooting from the first-floor door and windows, state officials said.The cause of the fire is under investigation, Kenworthy said.

No working smoke alarms have been found so far, state officials said.

Tell City Mayor Jim Adams called the incident a "tragedy."

"This is between Christmas and New Years. This is supposed to be a joyous time and this really kind of takes the bite out of that," Adams said. "I just want to let everybody know that we as a city, we want to just kind of wrap our arms around these family members. We want them to know they're not alone."

"I would reach out to the community and ask for their help in any way that they can as far as the family, not only with the children that have lost their lives in this fire but also with the remainder of the family right now in the hospital," he said at the news conference.

The Tell City-Troy Township School District said the "community lost three wonderful children, full of potential."

"Our hearts are heavy," the district wrote in a Facebook post. "Our thoughts and prayers are with the family in this trying time. Counselors and social workers are standing by to assist those impacted by this tragedy."

ABC News' Cheryl Gendron contributed to this report.