Unbelievable dust storm in Phoenix on 8/18/11!

It was the third major dust storm to hit the Phoenix metro area since last month. A storm on July 5 brought a mile-high wall of dust that halted airline flights, knocked out power for 10,000 people and covered everything in its path with a thick sheet of dust. Another dust storm hit July 18 reaching heights of 3,000 to 4,000 feet, delaying flights and cutting off power for more than 2,000