Sources aside, lets be a little realistic here.

Carthage was a huge and well-fortified city, surrounded by over 20 miles of circuit walls. Difficult to approach and with its own harbor, it was very hard to be surrounded and blockaded by Scipio's army to begin with. An especially strong tiple line of defence was based principaly on a wall 30 feet wide and 50-60 feet tall, fronted by a 60 foot ditch and timber palisade, running across the 3 mile wide isthmus approaching the city. The wall itself had two stories of rooms containing on the ground floor accomodation for 300--yeah, 300!--elephants, and above stables for 4000 horses and barracks for 20,000 foot and 4000 cavalry. True, in 149 the defenders lacked a well organized army and no evidence suggests they had any numbers of animals, but numerous volunteers ensured the defences were properly manned nontheless.

Yes, Carthage was destroyed. Sources say a senatorial comission arrived to supervise the systematic descruction--much of the city had already been destroyed by fire, and even today the archaeological site has burnt material still revealed. alot of the remaining buildings were destroyed, but it was not as complete as usually suggested. Archaeologists have discovered walls still standing several yards high beneath the Roman city. The earth being salted is a much later invention.