[shadowman99]

"I'm curious--assuming that this is a charter flight, with few passengers in a craft often used for charters...why so early in the AM?"

Looks like they were flying in before the start of somebody's business day.

[Mamzelle]

Yes, it turns out they were meeting passengers in Houston...explains the early, dark, foggy flight in...

link, all three dead were staff. Two pilots, one attendant.