Nightly News | March 22, 2014
and we have more tonight on an extraordinary scene that took place in recent days in colorado, where firefighters found themselves witnessing a rare event -- a fiery whirlwind, fed by an invasion of tumbleweeds, and all of it was captured by a firefighter with a camera. we get more tonight from nbc´s kristen dahlgren.
>> dahlgren: it was supposed to be a controlled burn , but this was anything but... when a dust devil kicked up in a wildlife refuge near denver...
>> man: how many times do you see that?
>> man #2: not real often.
>> dahlgren: ...picking up hundreds of fiery tumbleweeds and placing firefighters directly in their path.
>> rogers: there´s nothing we can do except get out of the way and wait for it to calm down.
>> dahlgren: thomas rogers has been fighting fires for seven years and was behind the camera when the dust devil spun out of control.
>> rogers: it was definitely interesting to see. i´m a fire buff, as well as a weather buff, and here i had a weather event and a fire event coming together.
>> dahlgren: dust devils usually form on clear, sunny days , when hot air near the earth´s surface rises quickly through cooler air above, causing a twister effect. this time, all those tumbleweeds and the controlled burn were added to the mix, kicking up a dangerous combination -- dry, fiery tinder flying through the air.
>> wilson: you get that hot air within the fire rising. then you take the winds from the environment, and that allows that whirlwind to set up. this doesn´t happen often.
>> dahlgren: a reminder of how unpredictable fires, even those that are deliberately set, can be.
>> rogers: any time there´s heating, unstable atmosphere, high winds , the fire danger is very high, with wind probably being the biggest component.
>> dahlgren: this time, the dust devil lasted for just five minutes, no injuries, and firefighters were able to stop the spread and get it back under control. but many out west fear this might be a sign of things to come -- a dangerous fire season following a record dry winter. kristen dahlgren, nbc news, new york.