The suspects had escaped the bank near Walt Disney World with one hostage Tuesday evening, but authorities cornered them in their getaway car, said Osceola County Sheriff Bob Hansell.
The male suspect then "used the hostage again as a shield to get into another vehicle," Hansell said. "He tried to leave again and at that point he was taken down by one of our snipers."
Deputies had been using cell phones to negotiate with the suspects, a man and a woman wearing masks, wigs and coats. They held four hostages at one point, but released three.
The hostages said they were treated well and were not threatened with violence, Hansell said.
It was not immediately clear whether the suspects made off with any money.
The standoff at the Mercantile Bank, a mile west of Disney, forced police to shut down the area, leaving some tourists confined to their hotels for much of the day.
Around 7:15 p.m., police blasted through the bank's rear door using an explosive device. The suspects escaped with a female hostage and drove away in a bank employee's car, but they traveled less than a mile before street barricades stopped them.
Shots were fired at deputies but nobody was hurt, police said.
The suspects had been holed up in the bank since Tuesday morning.
The first hostage was released when the robbers panicked when deputies arrived so quickly after the robbery, said sheriff's spokeswoman Twis Lizasuain.
The second was freed in exchange for cigarettes and the third after deputies agreed to back their vehicles a few feet farther away from the bank, Lizasuain said.
The suspects told authorities they did not intend to harm anyone, Lizasuain said.
Valerie Balkeway, who lives near the bank, said she feels safe in the neighborhood despite Tuesday's standoff.
"I feel very safe walking around here," Balkeway said. "If it hadn't been the suspect being killed, it would have been the hostage."
The same bank was robbed Nov. 16, and investigators are still looking for two suspects, Lizasuain said.