A massive new rock fall has hit Yosemite National Park, cracking with a thundering roar off the El Capitan rock formation, injuring one person and sending huge plumes of white dust surging through the valley floor below.

Hundreds of firefighters have been deployed to protect mountain communities in the path of a fire raging north of Yosemite National Park.

A giant wildfire raging out of control in the US has grown to nearly 200 square miles and spread into Yosemite National Park, as California Governor Jerry Brown declared a state of emergency for the city of San Francisco 150 miles away because of the threat to the city’s utilities.