The Wichita Police Facebook Page has an explanation of the incident near the Keeper.
On Friday evening September 16th, the Police Helicopter responded to the dispatched call of a "Submersion" near the "Keeper of the Plains" sculpture. A gentleman riding his bicycle apparently suffered a medical episode which caused him to crash his bicycle into the Arkansas River. Several citizens who happened to be walking and running in the area stopped to render assistance. They were able to keep the victim's head above the water, but had difficulty fully extricating him from the River. The Air Section was the first Police Department Unit on scene and was able to direct other emergency responders to the man's exact location. As additional assistance arrived on scene, the victim was pulled from the River and immediately transported to a local hospital. The Police Helicopter's Aircrew would like to give a big shout out and thank you to all of the citizens who took the time to get involved, call 911 to report the emergency, and actively assist during a time of immediate crisis!