More than 12 years after these two towers came crashing down... a memorial rises from their ruins.<br/> <br />In New York, just above the twin reflecting pools, the National September 11 Memorial Museum is on the verge of opening.<br/> <br />Inside, gut-wrenching sights of a dark day.<br/> <br />The museum recalls Sept. 11, 2001, when hijacked planes slammed into the World Trade Center's twin towers, the Pentagon and a field near Shanksville, Pennsylvania.<br/> <br />Nearly 3,000 people were killed.<br/> <br />The historical exhibition shows artifacts like wrecked emergency vehicles and various items buried in the rubble.<br/> <br />The museum is the result of eight years of work.<br/> <br />One hall features a retaining wall that survived the attack.<br/> <br />There's also a 36-foot column covered with mementoes, inscriptions and missing posters.<br/> <br />The museum opens on Thursday for victims' family members and on May 21 for the general public.
