The accident occurred around 9:45 p.m. Thursday as customers were watching the Miami Heat play the San Antonio Spurs.
Miami-Dade Fire Chief David Downey said 24 people were taken to area hospitals. Many had cuts and bruises, though one person suffered a fracture, a fire official said. Two people were in serious condition.
Authorities said about 100 people were on the deck of Shuckers Bar & Grill in North Bay Village, north of Miami Beach, when it gave way. The deck was about 8 to 10 feet above the water's surface, about the same height as a sea wall that runs along the bay.
Friday morning, a small U.S. Coast Guard vessel was anchored off shore. The dock, which collapsed in a v-shape, was strewn with large potted palms, green plastic chairs and tables, and umbrellas. Some flip-flops and cellphones were scattered among sugar packets, mustard bottles and other condiments from the tables.
"I'm trying to see why the supports collapsed," structural engineer Morgan Villanueva said Friday as he arrived to inspect the dock. He said it appears a main beam on the western edge of the dock buckled, creating the collapse.
Villanueva said Florida building codes typically call for a deck that can support about 100 pounds per square foot.
"If people (watching the NBA Finals) were excited and jumping, it's going to be an additional load," he said.
Griselle Marino, spokeswoman for Miami-Dade Fire Rescue, said Shuckers had passed a fire safety inspection in January. She said the restaurant's main structure had a capacity of 74 people, but the rules for the deck would be enforced separately by North Bay Village city officials.
Marino said it's largely up to restaurant and bar operators to ensure they don't go over capacity.
"We can't be policing every restaurant," she said.
Right after the collapse, sports bar customers — and later rescuers — helped people from the water amid yelling, crying and a rush to find people who might be submerged.
One witness, Martin Torres, 42, of Los Angeles, said he was inside the sports bar with family and friends when heard what sounded like a loud explosion. At first, he thought a boat had struck the deck. He said he looked outside and saw people staring up from the water, and then he and others started helping them out of the bay.
"It was shock," said Torres. "People were yelling. Nobody knew. People came out all wet. They were crying. For a while, nobody knows what was going on."
Israel Marquez, 37, of Bakersfield, Calif., who like Torres was in Florida because he's scheduled to board a cruise on Friday, said he "heard a big old snap. Boom. Like a shotgun blast."
Marquez said he looked out at the deck, and "it all came down in slow motion."
Many people seemed in shock, with cuts and gashes on their faces. He said he went to the edge and helped five or six people from the water before rescuers arrived.
"A lot of people were just shaken up," added Eric Williams, 42, of Atlanta. He rushed to the scene with his son, and they jumped in to help people after they heard a loud noise from their room at the adjacent Best Western.
He described the scene as "pandemonium," with people scrambling to get out.
There was initially some concern that people might have been trapped in the water beneath the crumpled deck. But divers searched the waters as helicopters overhead shined spotlights onto the scene, and Downey said later that everyone was accounted for.
"There were a lot of TVs and everybody was in celebration and it was loud. So when it started happening, some people didn't even realize what was going on," said Miami-Dade Fire Rescue spokeswoman Griselle Marino.
Heat player Dwyane Wade said after the game that his thoughts were with the injured fans.
"I'd like to share our concerns as an organization and our gratitude to our fans back in Miami, but share our concerns for all that were injured tonight at Shuckers restaurant," he said.
North Bay Village is a small island in Biscayne Bay with a strip of restaurants, hotels, houses and condos that is attached by causeways to the mainland and also to Miami Beach. Pouring rain fell early Friday near the Shuckers site, where a reporter later observed pilings sticking out of the water where the deck once stood. Wood, chairs and palm trees were piled together in the water in a scene like after a hurricane.
Although not as trendy as South Beach, North Bay Village is one of the many tourist spots in and around Miami where locals and visitors converge.
Cormier reported from Atlanta. AP photographer Alan Diaz and Associated Press writers Curt Anderson in Miami, Jackie Quinn in Washington and AP Basketball Writer Jon Krawczynski in San Antonio contributed to this report.