Paonia, CO – Kansas City Star — Three youngsters were missing and 16 other persons were injured after an explosion destroyed a remote mountain lodge as people were arriving for a family reunion, authorities said Sunday.

The missing youngsters, ages 3, 12, and 15, were from the same family, Delta County Sheriff Fred McKee said. “We are very concerned that they were last seen in the lodge,” he said.

Propane, which was used for heating, may have caused the blast, McKee said.

Authorities on Sunday afternoon called off the active search for the three. The charred rubble was too hot for searchers to enter the lodge, and snow made it impossible to get heavy search equipment to the site.

The missing children were from the same extended family that owned the lodge, McKee said. Their names were not released.