Witnesses said three young children had to jump out of a window to escape a fire in southwest Houston Thursday night.

The fire happened at a condo near Westward and Hillcroft. Neighbors think the children, ages 10, 6 and 3, may have been left alone in the apartment. They said the kids jumped out of a window and then ran downstairs to alert neighbors of the fire.

Fire officials said there was extensive damage to the unit where the fire started, and water damage to the unit below it. No one was injured.

Officials were investigating the cause of the fire. Arson investigators were on the scene.