 well you would definitely have the roof secured and you can secure that roof a number of different ways you can station an officer on the roof yeah you can make sure that any access to the roof such as stairwells outside access is secure and locked down so no one can actually get on the roof so there's a variety of different ways obviously that didn't happen here and the question is why did it not happen was it not planned for did no one anticipate did no one have the imagination that someone could get on that roof and so they didn't even think about it