A close family friend had a TBI and the road to recovery was long and slow and he never did fully recover
He was in a coma for about a month or so, maybe a bit less. He was at Metro, which has an excellent neuro area around here. He never regained full mental capacities, especially in math skills. He never could finish college because of it. He's able to lead an almost completely normal life though.
A well known dressage rider suffered a TBI. She fell off a horse and wasn't wearing a helmet. (Not saying a helmet would have definitively prevented any injury though!) She's on the road to recovery now and though she is starting back with some theraputic riding, it is still too soon to tell how much she will be able to do. It's such a shame. Shameless plug: Please wear a properly fitted helmet! It may not prevent an injury but it's better than nothing!
All my prayers are with the families of the victims.