I live in Tampa and have been watching the local news reports all night. The pilot was a 15-year-old pre-solo student. He had a dual lesson scheduled for late Saturday afternoon from St Pete-Clearwater airport. His instructor sent him out alone to preflight the aircraft. It seems the student started up, taxied out, and took off, solo, without talking to anyone. In other words, he stole the airplane. The tower, obviously, became aware of his actions and asked a H-60 Coast Guard helicopter, which happened to be awaiting takeoff. to give chase.
The helicopter rejoined with the student pilot over MacDill Air Force Base (which just happens to house US Central Command -- which is running the Afghanistan operation) and tried to get the student pilot to land at Peter O'Night airport in south Tampa. The pilot ignored the visual signals and then proceeded to fly directly into the tallest building in Tampa with the Coast Guard H-60 in chase.
The good news is the only injury/fatality was to the student pilot, and the building damage will be relatively minor.
This was a very tragic incident for all involved. But I suspect it may turn out to be just a unique way for a disturbed teenager to commit suicide.