Transcript for Decks collapse at three-story rental home on the Jersey Shore
now closer to home and a breaking story we're following overnight. Decks collapsing at a three-story home on the Jersey shore. This happened to take place during the annual New Jersey firemen's convention, so first responders who wound up needing help themselves. ABC's Kaylee Hartung is right there in wildwood, New Jersey, with the latest. Kaylee, good morning to you. Reporter: Hey, good morning, Dan. When you see these two decks stacked on top of each other, it is a wonder no one was killed. So the third story deck falling on the second story deck sending them both crashing to the ground. You can now see the exposed frame of the house there, and you'll notice the roof, it's unsupported. Overnight a terrifying scene in New Jersey. This multi-level deck collapsing trapping several people underneath the rubble. Ems respond across the street from 233 east baker for a structural collapse. Reporter: Neighbors and witnesses quickly jumping into action. I could hear the people over there calling for help, and I told the dispatcher what happened, where I was, and they sent the people out. Reporter: Emergency crews rushing to the complex working to free those stuck under debris. 225 east baker, multiple injuries reported. Reporter: At least 21 people hospitalized including 3 children. Branchville New Jersey fire chief Jon frato was on the middle deck with several of his fellow firefighters and their family members, all visiting for a convention. The upper deck came down on top of us, which made us trapped. It was just a lot of yelling and screaming going on. Reporter: A 4-month-old among the injured. A fireman heroically saving another young child trapped on a portion of the deck left standing after the initial crash. He climbed up the rubble, grabbed her off the deck, and at that same time of him grabbing it, that half of the deck collapsed. Reporter: Earlier this summer nearly a hundred were injured when this collapsed in Maryland and in 2016 more than a dozen were hurt after a deck gave out during a party in New York. One person here transported to a regional trauma center but of the more than 20 others hospitalized, 11 have been treated and released including the three children. Eva. Kaylee Hartung for us in wildwood, New Jersey.
This transcript has been automatically generated and may not be 100% accurate.