The Mackinac Bridge issued a warning to traffic on Sunday June 11th due to poor visibility and High winds. See the video here. 

The Mackinac Bridge Authority posted a video to their Facebook page showing the conditions on the bridge at the time of it's closing.

Part of the video description read,

Currently we are experiencing winds of sufficient force in the Straits area to issue a warning to all motorists preparing to cross the Mackinac Bridge.

BONUS VIDEO: Hot air balloon over Kalamazoo and Portage