If these chillers are connected to BACnet or similar network, then I wouldn't rule out the possibility of an attack.
>This sort of mass failure seems to point>towards either design issues (like equipment >selection/configuration vs
>temperature range for the location), systemic maintenance issues, or
>some sort of single failure point that could take all the chillers out,
>none of which I'd be happy to see in a data center.
If these chillers are connected to BACnet or similar network, then I wouldn't rule out the possibility of an attack.