Here is the link to the news video right after.
Reporter does say that there was a 2nd Bomb detonated.
From thier news helicopter. KFOR.com
(sorry about the long link)
http://www.kfor.com/global/video/popup/pop_player.asp?ClipID1=540577&h1=One%20dead%20after%20explosion%20outside%20OU%20stadium&vt1=v&at1=News&d1=66933&LaunchPageAdTag=News&activePane=info&playerVersion=1&rnd=5169822
video not loading presently