Yellowstone National Park Public Affairs confirmed that there could be a supervolcano eruption imminently - and that they were putting themselves through their paces so that they were ready for any eventuality.

Spokesman Morgan Warthin said: "Every opportunity like this, every training opportunity reveals both where our strengths are.

"But also how we can improve."

Mr Warthin knows that emergency services will need to be absolutely prepared if a catastrophe strikes near Mammoth in Yellowstone National Park.

A model bus crash was simulated for the first time in several years, in order to steel emergency workers for a crisis.

The exercise took place on a discreet road behind employee housing in order to minimise local disturbance, while the simulation was underway.

The Yellowstone spokesman also discussed the challenges his team will face if there is a supervolcanic eruption at Yellowstone.

He said: "You know, the number one challenge is we are remote, so it takes a while to get to Yellowstone."