A British Airways plane bound for London has caught fire at Las Vegas airport, forcing the evacuation of 170 people on board on emergency slides.
Airport officials said at least 14 people were taken to hospital with minor injuries.
US Federal Aviation Administration spokesman Ian Gregor said the left engine of the Boeing 777-200 caught fire before take-off.
The plane was seen engulfed in flames and smoke. The fire was later put out.
In a statement, British Airways said the aircraft "experienced a technical issue as it was preparing for take-off".
In a distress call the plane's captain asked for the airport's emergency services: "Speedbird Mayday Mayday. Speedbird 2276 request fire services."
"Speedbird 2276 heavy, we are evacuating on the runway. We have a fire, repeat, we are evacuating," he adds.
The pilot later told passengers that the accident was the result of a "catastrophic failure of the engine", reports the Guardian's Jacob Steinberg, who was on board the plane.
"We looked out the window and for the first time saw smoke near the wing. We could smell it. It was like burning rubber - bitter and deeply unpleasant - and it was time to panic," Steinberg writes.
Analysis: Richard Westcott, BBC Transport correspondent
Most pilots will go through their whole career without having to deal with an emergency like this, but it's always on their minds.
During every inch of a take-off, they are constantly thinking, "if something happens, what would we do?". They'll have discussed it before each flight too, talking through each possible emergency scenario and how they would handle it.
And they'll have practised it every six months or so in the simulator, aborting take-offs.
Above 180mph (290km/h), they would be forced to take off in this kind of plane, no matter what the problem was, because there is not enough runway to stop. Below that speed they have to make split second decisions, how bad is it? Do we throw on the brakes? Do we evacuate?
This flight was travelling at around 89mph when they decided to abort.
One experienced airline pilot told me that this BA crew seems to have reacted in a "text-book" fashion, getting everyone off quickly and safely.
Flight 2276 was bound for London's Gatwick airport.
There were 157 passengers and 13 crew members on board.
A spokesman for Rolls Royce told Reuters news agency the engine was not made by the company, British Airways uses engines made by either Rolls Royce or General Electric, the agency adds.
The airport tweeted: "Received first call at 4:13 PM (23:13 GMT); flames were spotted at 4:14, and by 4:14 response was underway."
It added: "@LASairport had the fire out and all passengers off BA flight by 4:18 PM - excellent work by our ARFF team."
Airport officials said passengers were taken to the city's Sunrise hospital, most of them with injuries sustained while sliding down inflatable chutes during the evacuation.
Some of those on board said there was smoke in the cabin as one exit was opened and immediately declared unsafe.
Eyewitness Reggie Bugmuncher said she was waiting at a gate for her flight when she heard people saying: "Oh, my God."
She said looked out the window and could see "bursts of flames coming out of the middle of the plane", the Associated Press news agency reports.
An investigation into the blaze is now under way after what was clearly a lucky escape, the BBC's James Cook in Los Angeles reports.
The incident shut one of the airport's four runways for several hours.
McCarran is a major airport in the US, handling more than 40 million passengers last year.