Colorado Springs firefighters quickly responded to a grass fire Tuesday afternoon.

Firefighters said an acre on a hillside burned around 2:30 p.m. on the northbound entrance ramp of Powers Boulevard near Woodmen Road. 

Several crews arrived to douse the flames.  The bottom of the hillside is littered with cigarette butts, and firefighters believe a spark from one possibly thrown from a passing vehicle ignited the fire.

"Had the fire moved up this hill and there was a house there, that could have been a structure fire," said Lt. Mark Trudell of the city Fire Department.  "Now, more than ever, this is how dangerous it is to carelessly toss a lighted cigarette butt."

Trudell said firefighters have responded to many reported fires but usually put them out before they become serious.