Back then, the community speculated countless reasons, like program crashes, system bugs, etc., but it turned out to be CME Group's main data center. On-site staff forgot to drain the water from the cooling tower before the temperature dropped to freezing, resulting in the cooling system for the servers freezing up and failing to function properly. In the end, server temperatures kept skyrocketing, and the world's largest futures exchange was forced to shut down for 10 hours. What a massive amateur move by the world...