It is very good news that no one was seriously injured.
BA has put the following on its website
Serious Incident involving BA
Updated 09/09/2015 05.04 AM (UK time)
The safety of our customers and crew is always our priority, and we are looking after those who were on board the BA2276 from Las Vegas to London Gatwick following an incident on Tuesday September 8, 2015.
The aircraft, a 777-200, experienced a technical issue as it was preparing for take-off from McCarran International Airport in Las Vegas.
Our crew evacuated the aircraft safely and the fire was quickly extinguished by the emergency services at the airport.
157 customers were on board the flight, along with three pilots and 10 cabin crew.
A small number of customers and our crew have been taken to hospital as a precaution.
All customers have been provided with hotel accommodation, and our colleagues are helping them with anything further they require.
We will provide any further updates on ba.com.
Friends or family with any concerns can call +800 1360 7012.
I imagine this will be updated – the link is here
The photos and footage on various media (and social media) channels show how bad the situation was – and could have been.
I’m sure passengers and crew stayed calm during the evacuation. So calm, in fact, that some evacuated with their hand baggage. Much comment about that on social media!