A major snowstorm has hit the US state of Colorado, forcing the cancellation of hundreds of flights at Denver's main airport and causing chaos on the roads.
Many passengers had to spend the night at Denver airport
The storm - the second in a week - dumped up to 28 inches (71cm) in parts of the western state on Friday.
More than 300 flights were cancelled at Denver, and Interstate 25 - the main road through the state - was closed.
Colorado Governor Bill Owens declared a state-wide disaster, putting the National Guard on standby.
United Airlines and Frontier Airlines, the largest carriers at Denver International Airport, cancelled 322 flights on Friday morning, according to the Associated Press news agency.
The storm dumped up to 28 inches (71cm) of snow in some areas
The authorities at the fifth-busiest US airport drew up emergency plans to deal with the blizzard.
Extra workers were called in to help stranded passengers, many of whom were informed that they could only leave after the storm.
But a United Airlines spokeswoman was quoted by the AP as saying that the company was "planning to operate a full schedule starting at noon".
The storm also forced the authorities to shut down several major roads in northern Colorado, including Interstate 25.
A major bus operator cancelled all trips out of Denver, and more traffic chaos was expected over the weekend.
Last week's storm paralysed Colorado's biggest cities and caused the cancellation of more than 1,000 flights at Denver.