Has the location for your data center facility been properly vetted? There are many considerations, and they have evolved considerably since many existing data centers were constructed and put into production.
Basic Data Center Location Requirements
First, from TIA-924-A-2012 (these are very basic requirements; they must be satisfied before any discussion of Tier 3 or higher takes place):
If cooling equipment, generators, fuel tanks, or access provider equipment is situated outside the customer space, then this equipment should be adequately secured. In the Midwest, this also means sustaining a 120 MPH wind load.