"Originally, I thought that something odd was going on," said Danielle Arno, Centennial resident. "There were so many of them. It was probablythe most incredible thing I've ever seen."

Arno was one of hundreds of people who saw the lights cross the sky across the South Metro Thursday night.

"So, I got in the car and came down to see if I could find out what was going on and ended up here at a wedding reception," Arno said.

It was actually the rehearsal dinnerwas for the wedding of basketball player James "Jimmer" Fredette. He currently plays guard for the Sacramento Kings.After his senior year at Brigham Young University, Fredette was recognizedasCollege Basketball Player ofthe Year.

"Paper lanterns at the rehearsal dinner! AMAZING! Such a perfect night!" his bride-to-be, Whitney Wonnacott,said in a tweet.

The wedding is scheduled for Friday night.

Viewers called in to 9NEWS to report"strange fiery lights" floating in the sky. One viewer finally solved the mystery after one of the lanterns landed inher neighbor's yard.

9NEWS photographer Brian Willie shot video of the lanterns in the sky near Arapahoe and University.

Chinese Sky Lanterns are advertised as being designed with "safety in mind". The balloons are made of a material that is flame-retardant.

Still, fire fighters say launching these lanterns is a bad idea.

"We want people to be especially careful this time of year when it has been so dry, when it continues to be dry," Andy Lyon, public information officer for South Metro Fire Rescue said. "Especially the thought of launching these into the sky not knowing where they're gonna go or come down or when, that's just ridiculous."