Deleting Rows From Many Tables

What I'm trying to do is delete a user and all their related information within the other tables. I'm not wanting to delete the table, just one column with that user and their related information. So my Primary_Key is UserID within the table [alumni] and my three Foreign_Keys are CommentID, PhotoID, and AlbumID within the tables [comments], [photos], and [albums]. Here is some of the code that I have:

<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:SoderquistString %>"

DeleteCommand="DELETE FROM [alumni] WHERE [UserID] = @UserID"

SelectCommand="SELECT [UserID], [UserName], [FirstName], [LastName], [State] FROM [alumni] WHERE ([State] = @State)">

<DeleteParameters>

<asp:Parameter Name="UserID" Type="Int32" />

</DeleteParameters>

<SelectParameters>

<asp:ControlParameter ControlID="DropDownList1" Name="state" PropertyName="SelectedValue"

Type="String" />

</SelectParameters>

</asp:SqlDataSource>

The users are set up in GridView form. Is there some type of DELETE command that I need to be writing that is different than the one above? I have tried adding onto the following DELETE statment:

DeleteCommand="DELETE FROM [alumni] WHERE [UserID] = @UserID

DELETE FROM [photo] WHERE [UserID] = @UserID;

DELETE FROM [album] WHERE [UserID] = @UserID;

DELETE FROM [comment] WHERE [UserID] = @UserID;

...but that doesn't work...and doesn't look right. I would really appreciate anyones suggestions or help that you may be able to provide. Thank you!