What we know about the explosion of an engine on a Boeing 777 flying over Denver in the US

A Boeing 777 operated by United Airlines had to make an emergency landing in Denver at the weekend after one of its engines blew apart.

The explosion resulted in huge chunks of wreckage crashing down across suburban neighbourhoods.

Passengers captured video of the crippled engine, wobbling and still on fire, as pilots made a safe return to the airport minutes after the plane bound for Hawaii took off.

Now the investigation into the explosion is focusing on broken fan blades — a similar development to what followed a fatal failure on another plane in 2018.

This is what we know so far.

So, what do authorities think happened?

US officials say two fan blades on the Boeing 777’sPratt & Whitney engine broke off.

Experts say it’s likely one blade…