How can twin tower sit on the ground while in crash with a heavy plane of very high speed. THINK AMERICANS THI?

How does the twin towers sits on ground after the crash because according to scientific and engineering point of view it should have fallen side wise because it was crashed with a great plane of high speed sidewise so if there were some dynamite charges underneath the towers then they should fall straight down.it means that the twin towers bases were bursted with dynamite charges when the plane crashed.now think yourself is'nt the alqaeda a dramatic character.