BOULDER, Colo. -- A small plane clipped the towline of another plane pulling a glider Saturday, sparking a fiery midair crash in Colorado and killing at least three people, authorities said.
The glider disconnected from the plane just before the second plane hit the tow rope, Boulder County sheriff's office spokesman Rick Brough said.
NTSB field investigator Jennifer Rodi said the accident happened at about 1:30 p.m. near the Boulder Municipal Airport.
The glider landed safely -- with no injuries to any of the three people on board -- just after the planes made impact, authorities said.
"We understand the glider went through a fireball after the impact," Rodi said.
Brough said one of the planes, a Piper Pawnee, belonged to Mile High Gliding Inc. and had just taken off from the Boulder airport with the glider in tow shortly before the accident happened.
A woman who answered the phone at the glider company declined to comment.
Gliders, or sailplanes, are lightweight aircraft that are often towed into the sky, then released to glide to the ground.
The crash spread debris over a 1Â½ mile region, scorching several sections of prairie in the Rocky Mountain foothills. The crash happened near a suburban area dotted with homes and businesses, but no one on the ground was injured.
It was unclear from where the single-engine, four-seat Cirrus SR20 that clipped the tow line took off. Tail numbers were not immediately available.
An amateur video shot at the scene showed a plane on fire, floating to the ground trailing thick, black smoke and a parachute.
Brough said the parachute was designed to deploy if a plane was disabled and was attached to the plane's wreckage, not a pilot or passenger.
Brough said there were no survivors from the crash. Authorities were still trying to confirm who the victims were.
It was unclear why the Cirrus got close enough to the Piper Pawnee to clip its towline.