UPDATE (11:48 EST): We’ve been told by our CDN provider that everything should be back to normal now.
Currently, our CDN provider is under a DDoS attack in Dallas. This means that anyone in that region using the CDN will likely be seeing slow page loads, as well as missing images and styling. This is something that our CDN provider is actively working to remedy, and they are expecting to have their systems running normally within the hour.
For anyone who is seeing this problem on their site, you can temporarily disable the CDN by going to your WP Engine menu in the WordPress Dashboard, then go down to the CDN section, and change the box to “Disabled”, and then save.
This does not appear to be affecting all regions of the CDN, so depending on your location, you may not be seeing any problem.