A wall of dust descends on parts of Phoenix, Arizona, drastically reducing visibility and delaying flights as strong winds cause power outages for thousands of residents.
Please wait while this video loads. If it doesn't load after a few seconds you may need to have Adobe Flash installed.
A massive cloud of dust engulfed skyscrapers, roads and an airport on Tuesday night in the US city of Phoenix.
The cloud appeared to be 50 miles wide in some areas and towered over buildings, according to local reports.
Footage captured from a helicopter showed the storm rolling through the city and blanketing downtown Phoenix as night fell.
The storm was a part of monsoon season, which typically starts in mid-June and lasts through to the end of September.
Strong winds, with gusts of more than 60 miles an hour, rapidly moved the dust cloud north west through Phoenix and the cities of Avondale, Tempe and Scottsdale.
More than a dozen communities in the area were placed under a severe thunderstorm watch until 11pm local time (0600 GMT).
As the storm moved through the area, up to 8,000 utility customers were left without power.
The Arizona Republic reported winds also downed live wires in Tempe that sparked a fire at a busy intersection, but firefighters were able to quickly extinguish the blaze.
The Federal Aviation Administration said on its website that due to low visibility in the area, no Phoenix-bound flights were allowed to leave Las Vegas or Los Angeles airports until 9pm (0400 GMT), and flights at the airport were grounded for about an hour.
Over 3,000 people were forced to leave their homes in June as Arizona's second largest ever wildfire, dubbed the Wallow Fire, raged for over 10 days.
Officials said the huge blaze charred more than 311,000 acres of pine forests since it began in May.
Arizona's neighbouring state, New Mexico, banned the sale of fireworks earlier this week as a severe drought grips the southern United States.
The dry conditions - the result of an exceptionally severe La Nina weather pattern which is a cooling of the tropical Pacific Ocean - has sparked wildfires across the south of America.
08 June 2011
04 July 2011