Transcript for Waterfront Bar Collapses During NBA Finals
stunning col the deck at a popular waterfront bar and grill in miami last night. So many people thrown into the water when it gave way. Some seriously injured. And abc's matt gutman is at the scene. Matt? Reporter: Good morning, josh. I want you to take a look at what's left of this deck. About 100 people were on top of it when it folded inside, like a book. There were people on there that that were collapsed inside, with chairs, tables, umbrellas. There were families there. The fear and the panic, indescribable. Cheers for the heat. Turned to screams of terror. All of a sudden, whoosh. And a crash of the deck. And tables and chairs and all that. People yelling. Reporter: Dozens spilled into the water of this popular miami sports bar. Overnight, rescue crews waded in murky water, fishing out dozens of survivors, like this woman. It started clicking. And it collapsed. Reporter: More than 30 were hurt, 2 critically. This exclusive video shows this wooden deck split in two. Right here, where this man was sitting. We were watching the game. And next thing we know, we heard screaming. We thought, naturally, because of the game. And we looked back, the whole dock behind us just dropped. And people were in the water. It was so crazy. Reporter: In the jumble of slippery wood and tables, jalen brown thought he couldn't scramble out of the water. We'll help you. We'll help you. And they pulled us to help. Everybody was frantic at that point. We pulled people out of the water and helped them get up. Reporter: You can see that the force of the collapse actually ripped up the concrete, one of the reason the officials here are calling it a mass casualty incident. They don't know what caused this. They don't know if it had anything to do with there being 100 people on the deck and over capacity. We do know, after the game, miami heat star dwyane wade expressed concern for his fans and the spectators. If there's any silver lining in this, it's that the heat won the game, tying up the series, 2-2.
This transcript has been automatically generated and may not be 100% accurate.