The TSW series and its 3rd gen family won't fire when dropped. With the safety on you will see the hammer sticking slighty further out than when the safety is off. This is because it has block between the hammer and the firing pin (pull back the hammer when the safety is on and you will see it). This will prevent accidental discharge under all but the most rediculous conditions.
That being said I have a 4006 (very similar design) that I never carry with the safety on. The design of these pistols is such that they won't go off unless you pull the trigger (again assuming all but the most rediculous conditions and what ifs). Best thing to do with this gun is carry it with one in the chamber and saftey off, but hammer decocked.

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J.D. Roy