里尔喷气机在佛罗里达坠毁，九人全部遇难

The 20-year-old co-pilot said over the radio, "We're going to crash into the ground."

Less than a minute later, the business jet carrying nine people fell into a residential street in Palm Beach County, Florida.

The plane exploded and caught fire; all nine people on board died, seven of them passengers and two crew members.

On the ground, one person sitting in a car was also injured; right next to the crash site are ballfields, shops and homes.

When a plane comes down in a place like this, the price paid is often not just by those on board.

The aircraft involved was a Learjet 60, a type that received certification back in the 1990s.

It took off that morning from an airport in Austin, Texas, bound for North Eleuthera in the Bahamas, and was operated by a company called Aurora Aviation.

Thomas Chapman of the National Transportation Safety Board described what happened during the high-altitude portion.

When the plane climbed to 35,000 feet, the crew reported light icing and moderate turbulence.

The fuselage began pitching up and down by several hundred feet, so the crew requested a climb to 37,000 feet.

But the situation did not improve.

In the mayday call, the pilot said, "We are descending at 10,000 feet per minute."

Right after that he said the plane had entered an overspeed condition, with a descent rate of 20,000 feet per minute.

Co-pilot Nathalia Filgueiras said over the radio that the plane was banking until it was almost on its side.

She said, "We're going to crash into the ground, we're out of time."

From the mayday call to the plane hitting the ground, only about a minute passed.

Chapman said the plane appeared to have broken apart as it fell.

Debris was scattered over an area about half a mile long, and investigators will have to examine it piece by piece.

He said weather is currently a major focus of the investigation.

Another focus is how the pilots and air-traffic controllers decided on that route at the time.

In Chapman's words, they need to establish who knew what and when, and what they did.

Among the dead were Captain Jeff Gregory and the 20-year-old Filgueiras.

Among the passengers was a Texas tech entrepreneur named Adam Robinson, who was on the plane with family and friends.

On the ground, residents of a nearby mobile home community were urgently evacuated.

Investigators have already begun work at the site, examining the wreckage and scattered parts.

The National Transportation Safety Board is an independent agency that specializes in investigating air disasters; it does not determine who is guilty, only what caused the crash.

The board also said it will look into whether this accident has similarities to several past accidents involving the same aircraft type.