Deleting Items In A List In A For...Next Block

[NinjaNic]

Hi!
I am trying to delete items in a list that have a location outside an 80x80 rectangle. Either if I create a temporary list or not, I get this error:
Collection was modified; enumeration operation may not execute.
It looks like the tempList.Count = 0, but I'm not sure why. (The DeleteExtra() sub is used in a timer.tick event.)

    Private Sub DeleteExtra()

        bmpList(0).LocationX = 2000 'Just to test!

        Dim TempList As List(Of bmp) = bmpList
        For Each bmp In TempList

            If bmp.LocationX < 0 Or bmp.LocationY < 0 Or bmp.LocationX > 80 Or bmp.LocationY > 80 Then
                bmpList.Remove(bmp)
            End If

        Next

    End Sub

Thanks in advance. ~NinjaNic