How to fire an event of an user control which is loaded multiple times?

I have 2 user controls: uc1.ascx & uc2.ascx. uc1.ascx has a panel and a data set, which loads an array of uc2 (panel.Controls.Add(uc2[i]) as the data set goes row by row. How do I fire a uc2 event, say a button click on uc2[1]? When I click, the entire panel becomes blank... 
Thanks!

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