TN is usually pretty good at their schedules and hit the dates over 90% of the time. Also, there is a very large incentive to open before those dates.
With my daughter directly involved in the process, it's very interesting seeing all of what must transpire from concept to completion. Amazing that anything gets done in a timely manner. But it is very surprising they can get the survey, design, and contract awarded in less than 72 hours of the incident, especially considering 48 of those hours were on the weekend.