A tornado touched down in Aurora Sunday, causing people in the area to run for cover.
"Then we started seeing debris spinning and as it got closer it became more obvious that there was papers and lumber and tree parts...then everyone started running inside," said Michael Celentano.
The storm also overturned construction trailers.
One person who was on a golf course when the storm blew through reportedly suffered non-life threatening injuries.
More than 16,000 lightning strikes were recorded in the Denver area.