Friends and family members gather at the 9/11 Memorial during ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York, Sept. 11, 2013. (AP Photo/Alejandra Villa, Pool)

NYC 9/11 museum opens to public in May

Officials at the National 9/11 Memorial in New York say the long-delayed museum dedicated to victims of the terror attack will open to the p…