Photos from the fire department showed the plane upright in tall grasses, surrounded by caution tape.
Jason Walker and his friends were in an adjacent parking lot when the plane landed.
When asked if they heard any signs of distress, Walker replied, "Nope. Somebody from the pool over there came out and said she saw it glide over the pool. Nobody heard it come in."
Sharon Knobel was at the Lakeshore Athletic Club pool, enjoying the sunshine, when she saw the plane fly overhead.
"It was coming in at a really sharp angle," she told 7NEWS, "but we heard absolutely nothing."
Knobel said the plane appeared to skim the top of a tree as it approached the golf course.
Todd Schumacher, a Broomfield city council member, tells a similar story. He was working out at a nearby athletic club when he looked out the window and saw the plane start to go down. He says the wings wobbled, and the plane glided past an apartment building and a large tree before landing.
Investigators say the pilot intended to land at Rocky Mountain Airport when the engine died. The names of the pilot and passenger have not been released.
The plane is registered to Sanborn Mapping, a company headquartered in Colorado Springs.
Knobel credits the pilot with keeping the surrounding neighborhood safe.
"There's a big Walmart over there," she said. "And a senior living center right next door. He avoided those areas."