The incident unfolded on Centennial Bridge when a man began firing shots at random at vehicles of the bridge,The Kansas City Star reported.
A soldier from the nearby Army installation who was waiting in traffic at the time stopped the gunman “by striking the shooter with his vehicle”, Leavenworth Police Chief Pat Kitchens said.
“What was a very, very dangerous situation, fortunately, was ended quite quickly,” Chief Kitchens said. “Again, very likely countless lives were saved by the person who intervened.”
Police said that the shooter had multiple weapons and was firing at cars with no particular association.
One person was hit during the shooting, identified by police as a second Fort Leavenworth soldier, who was said to have been in a serious but stable condition on Wednesday afternoon.
The shooter was also taken to hospital with serious injuries that were not life-threatening, Chief Kitchens said.
Two additional vehicles were reported to have been struck with gunfire during the episode, but it is believed that no-one else was injured, according to The Star.
A man who was beneath the bridge at the time of the attack told KSHB how he heard the incident unfold.
“I heard like nine or 10 shots up there, by then there was rapid fire,” Charlie Jordan told the broadcaster. “It was just, bam, bam, bam, bam, bam, bam. Just like fireworks.”
According to police, the motive of the shooter is as of yet unclear and they are still processing the crime scene.