Sad Day here in Miami,FL

All 20 aboard die as aircraft breaks apart, hits ocean.

MIAMI, Florida (CNN) -- Investigators are trying to raise the wreckage of a seaplane from the ocean floor off Miami as they try to determine what caused the craft to break apart and slam into the water, killing all 20 aboard.

The vintage seaplane was headed to the Bahamas when it went down Monday afternoon. Amateur video showed the plane coming apart and part of it slamming into the water in a fireball.

Mark Rosenker, acting NTSB chairman, said a salvage team would attach balloons to the pieces of the Grumman G73 airplane and try to lift them onto a barge Tuesday.

"It might be trucked to a hangar, but we'll do a preliminary investigation when it first gets on shore," Rosenker said.

Teams would also continue their search for the aircraft's cockpit voice recorder, he said, in the hopes it will contain clues about what caused the fiery crash of the seaplane, which was built in 1947.

Investigators said they are treating the incident as an accident and that one factor might have been the plane's age.

"We'll be looking at operations. We'll be looking at human factors," he told CNN, as well as the plane's structure and engines.

Divers were mapping the crash site Tuesday morning and documenting the debris field through photographs, Coast Guard Capt. James Maes told CNN.

There were no apparent survivors of the crash. Nineteen bodies were recovered Monday, and the U.S. Coast Guard will search again Tuesday for a 20th person.

The airplane, operated by Chalk's Ocean Airways, was carrying two pilots, 15 adult passengers and three infants to Bimini in the Bahamas. (Map)

The plane, which takes off and lands on the water, crashed about 2:30 p.m., officials said.

Amateur video shows what appears to be the fuselage slamming into the water, followed moments later by an object engulfed in a large ball of fire -- possibly one of its wings. Trails of thick black smoke could be seen in the sky. (Watch amateur video of the crash -- 0:26)

"That's a truly remarkable piece of film," said Robert Francis, the former chairman of the National Transportation Safety Board. "This piece of film will now allow the NTSB to prioritize, a little bit, what they're looking for in terms of the wreckage."

Witnesses had described hearing a loud explosion and seeing the plane break up.

One woman said the plane was flying "pretty low" and "a little bit loud," when, "all of a sudden, we just heard it blow up." (Watch witnesses describe the plane's plunge -- 1:52)

"I saw two pieces, and it went down into the water," she said.

Another witness said he saw the wing come off, and "it exploded."

The crash prompted an urgent search-and-rescue operation involving the Coast Guard, fire department and other emergency departments. Three Coast Guard search vessels, aided by private boats and at least one helicopter, scoured the waters.

Chalk's general manager, Roger Nair, said the crash of Flight 101 was the first crash of a plane carrying passengers since the company was founded in 1919.

"We are a close-knit, family airline, and most of our passengers have been our customers for an extended period of time," he said. (Airline history)

NTSB records confirmed that the airline had never had a fatal accident with passengers on board before Monday. However, one of Chalk's planes crashed in March 1994 near Key West, killing the two occupants, both pilots.

Monday's crash closed down the main ship channel leading from the Port of Miami, Maes said, adding the the channel will not reopen until the wreckage is removed.

"We're hoping we can reopen the channel sometime today," Maes said.

A spokeswoman for the FBI's Miami office said Monday two agents were sent to the site but that there was no evidence of foul play.