Four days after announcing U.S. forces had killed Al Qaeda leader Osama bin Laden, President Obama visited the World Trade Center where thousands were killed during the 9/11 terrorist attacks. The visit to Ground Zero was the first by Obama since he became president.

The president laid a red, white and blue reef on the site known as ground zero and met with relatives of the victims of the September 11, 2001 attacks. Obama was accompanied by former New York City Mayor Rudy Giuliani and other elected officials

The New York Post reported:

Obama was accompanied by elected officials from New York, including Sens. Chuck Schumer and Kirsten Gillibrand, as he laid a wreath at the foot of the Survivor Tree, which sustained damage during the attack but was freed from the rubble.

After the ceremony, Obama met with 60 family members of 9/11 victims during a private session.

Before heading to lower Manhattan, Obama stopped at a firehouse in Midtown that lost 15 men on 9/11 -- more than any other New York firehouse -- and had lunch with the firefighters.

"I wanted to just come up here to thank you," Obama said. "This is a symbolic site of the extraordinary sacrifice that was made on that terrible day almost 10 years ago." Obama also said bin Laden's death sent a message that "when we say we will never forget, we mean what we say.

The Christian Science Monitor reported that the event at ground zero:

seemed to provide some comfort to the families of those who lost loved ones on 9/11.

“Without a doubt, it certainly helps,” Alexander Santora, who lost his son, a firefighter, on 9/11 told the Monitor. “People keep asking, is there any kind of closure? There is never closure when you’ve lost a child, especially when you lose a child in such a horrific way. There is always a hole in your heart.”

It was a sentiment repeated by Obama. When he met with members of the New York Police Department, he told them he understood how hard it would be “to fill the hole that occurred as a consequence of losing folks you had worked with for so long.”

Bin Laden was killed Sunday during a raid by U.S. Navy SEALS in Pakistan. The president is scheduled to fly to Ft. Campbell, Kentucky Friday to visit with the Navy SEAL and others who took part in the operation.

Watch video of Obama as he lays a wreath at ground zero.