NTSB: Wilmette pilot killed in midair collision didn't see other plane

ROCK SPRINGS, Wyo. -- Investigators say the pilots of two planes that collided in the air near Rock Springs last summer failed to see each other's aircraft.

Three people were killed when the planes hit about six miles northeast of Rock Springs on Aug. 10.

The National Transportation Safety Board released its conclusions about the probable cause on Tuesday.

Investigators say one plane was preparing to land in Rock Springs, and an a traffic controller told the pilot the other plane was about 10 miles away.

Killed were 54-year-old Dave Knezovich of Rock Springs, 67-year-old Ralph Otto of Wilmette, and 67-year-old C. Michael Downey of Columbus, Ohio.

Knezovich, a student pilot, was alone in one plane. Otto was piloting the other plane and Downey was his passenger.