A 4-year-old boy and 7-year-old girl jumped from the second story of a burning duplex in St. Paul early this morning.

The kids jumped into the arms of neighbors who gathered in the 1000 block of Marion Street where the fire occured.

The fire was set in the back and blocked the only stairs from the upper level said St. Paul Fire Marshal Steve Zaccard.

The only person harmed was a 28-year-old woman who hurt her ankle while coming down a ladder and a firefighter who sustained light injuries after falling from the roof.

“When someone intentionally sets fire to an occupied residence like this, blocking their escape, they’re trying to kill someone,” Zaccard said. “Arson is not just a crime against property, it’s most certainly a crime against innocent people, too.”

Neighbors, awakened by the crackle of the fire, put mattresses on the ground and caught a 4-year-old boy and 7-year-old girl as they jumped from the second-story window, the fire marshal said. Firefighters placed a ladder to the window and rescued the man and woman.