The CNN article called a "Piper tourist plane"
That can be anything from an Archer to a Navaho Chieftain. A Navaho is a fairly large twin-engined plane (8-10 people) and is often used for tourist flights. It could do a lot of damage.
The article says the pilot radioed an SOS (actual term is Mayday) reporting engine trouble, so it's possible it was an accident instead of terrorism. Of course, the Mayday call could've been a ruse, too. When a pilot declares an emergency, he's given very wide latitude to get the plane down in a hurry, including such things as taking the shortest route back to the airport that normally might not be allowed.