On separate but related attacks, the Pentagon building near Washington d.c. was hit by a hijacked 757 at 9: 43 am, and at 10: 10 am, a fourth hijacked The south tower WTC 2, which had been hit second, was the first to suffer a complete structural collapse at 10: 05 am 62 minutes after being hit. The north tower, WTC 1, then also collapsed at 10: 29am, 104 minutes after being hit. WTC 7, a substantial 47 storey building in its own right, built 1987, was damaged by the collapsing towers, caught fife and later in the afternoon also totally collapsed• On separate but related attacks, the Pentagon building near Washington D.C. was hit by a hijacked 757 at 9:43 am, and at 10:10 am, a fourth hijacked The south tower, WTC 2, which had been hit second, was the first to suffer a complete structural collapse at 10:05 am, 62 minutes after being hit. The north tower, WTC 1, then also collapsed at 10:29am, 104 minutes after being hit. WTC 7, a substantial 47 storey building in its own right, built in 1987, was damaged by the collapsing towers, caught fire, and later in the afternoon also totally collapsed