DENISON, Texas (KTEN) — Two historic military planes collided and crashed during an air show in Dallas on Saturday.

One of the planes involved in the midair collision, a World War II vintage B-17 bomber, had paid a visit to North Texas Regional Airport in Denison back in 2017.

Perrin Air Force Base Museum volunteer Mary Day was saddened to learn this was the same aircraft she had toured five years ago. 

"I got the information and looked up tail numbers; I just couldn't believe this was the same plane I had been in," she said. 

Day expressed her condolences for the six aviators who died in Saturday's crash. The cause remains under investigation.