Twelve and a half years after the September 11th terrorist attacks, President Obama dedicated a museum on the subject in New York City Thursday.
The September Eleven Memorial is seven stories underground into the foundations of the Twin Towers. It holds more than 10,000 artifacts to capture the events of that day and to remember the nearly 3,000 people who died.
Among them is Denny Thedans' sister.
"God, I think about her every day," Thedans said.
Cheryle Sincock died as a hijacked plane hit the Pentagon where she had worked for 15 years.
The dedication of the new museum brings back painful memories, however, Thedans says they've never really left.
"To me there isn't such a word as closure," Thedans said. "I don't understand how people or how these law enforcement people can say we give you closure. God, when people get murdered like that, anybody gets killed like that, there ain't such a thing."
While nearly 13 years have passed since the attacks, Thedans says he's proud that his sister's memory will live on both in his heart and at the newly dedicated museum.
"We have to have this so that future generations know what is going on," Thedans said. "It's our way of remembering those people and make sure this never happens again."
For the next six days, the museum will be open around the clock for family members and survivors of the attack. It opens to the public on May 21.
Thedans hasn't made plans to attend but hopes to visit the museum soon.