People in Southern Florida have begun evacuations en masse as the deadly Hurricane Irma approaches. The Category 5 storm has claimed the lives of more than a dozen individuals so far with that number expected to rise.

Alarm has been raised at a sharp change in direction from Irma which had been expected to move north-east, straddling the Floridian coast and move towards South Carolina. But overnight, the storm changed path in a north-easterly direction which is set to take it directly through Florida.

Mandatory evacuations have been ordered in Miami-Dade County, Broward County, Palm Beach County, low-lying parts of Brevard County, and Monroe County, home to the Florida Keys. Evacuation orders now affect over 500,000 residents.

Monroe County Administrator Roman Gastesi issued a stark warning saying: "You might as well leave now, while you have a chance, because when you dial 911, you will not get an answer."

Miami is now directly in the path of the storm which has become one of the strongest to ever hit the Atlantic Basin. It has been able to sustain winds of more than 180mph despite making first landfall more than 48 hours ago.

The county of Miami-Dade is the most populous in the state with more than 2.5 million inhabitants expected to face the full force of Irma.

There are fuel shortages, mass traffic jams and empty supermarkets as more than half a million are expected to travel to northern parts of the state where the storm is expected to ease.

Florida Governor Rick Scott warned that if people wait until Saturday or Sunday (9 and 10 September) to leave, it will be too late.

"We cannot save you when the storm starts," Scott said. "So if you are in an evacuation zone and you need help, you need to tell us now. You do not want to leave on Saturday, driving through Florida with tropical storm force winds."

Echoing the comments from Governor Scott, Emergency services have warned that once the storm strikes, their ability to help will be curtailed. Hospitals are closing, ambulances are locked away and air ambulances are unable to fly. Officials have urged people to leave.