Raging flood waters are submerging Boulder, Colorado, and surrounding areas, where rescue operations are underway.
John Hoffenberg watches the flow of water increase in Boulder, Colorado, Sept. 15, 2013.
An aerial photo of a flood-affected area of northern Colorado along the Big Thompson River, Sept. 14, 2013. (U.S. Air National Guard Handout photo)
An aerial view of vehicles submerged in flood waters along the South Platte River near Greenley, Colorado, Sept. 14, 2013.
Children board a rescue helicopter flown by the U.S. Air National Guard after severe flooding shut down major roads leading out of Jamestown, Colorado, Sept. 14, 2013. (U.S. Air National Guard Handout photo)