UPDATE: This article claims that Houdini made a second leap from the Seventh Street bridge on March 13, 1908. The author appears to have gotten this from The Secret Life of Houdini, but I've yet to find any evidence of this escape. Also, Houdini was still performing in Detroit on this day. He didn't open in Pittsburgh until March 16. So I suspect the below photo is of his earlier May 22, 1907 jump.
For more on Houdini's Pittsburgh plunges, check out Joe Notaro's Did Houdini ever perform an overboard box escape in Pittsburgh? at HHCE.