KANSAS CITY, Mo. - Missouri officials are investigating what caused more than 50,000 fish to die in a stream near Kansas City.An estimated 50,000 sunfish, 1,900 common carp and 240 silver carp were killed in Brush Creek, a 10.5-mile-long stream running through Johnson County, Kansas, to Jackson County, Missouri, according to the state’s conservation department.Video recorded June 14 by Terrence McKelvy showed the dead fish floating in the water in a section of the stream that runs between Prospect Avenue and Benton Boulevard."Look at this," McKelvy says in the video, who was on a bike ride and stopped to record the footage when he noticed the dead fish. "These are all fish in Brush Creek.