The U.S. Embassy has confirmed via a spokesman that the remembrance is open to anyone.
The location is in the same park where a memorial was erected in 2004. The former Parque Urbanización General Cañas became the Parque 11 de Setiembre. There were ceremonies there for four years after the multiple tragedies, but then U.S. officials made the commemorations private affairs and held them inside the embassy grounds.
That is not the case this year, which marks the 10th anniversary of the terrorist attacks on the World Trade Center in New York, the Pentagon in Washington, D.C., and presumably the White House or U.S. Capitol Building.
The last commandeered jet crashed in Pennsylvania when its passengers battled hijackers so its target remains unknown.
Government sources report that 15 of the 19 hijackers were citizens of Saudi Arabia, as was the mastermind, Osama bin Laden.
Costa Rica has downplayed the anniversaries because it is seeking investments from the Arab world.
In the first three years after the attacks, Costa Rican firemen and police demonstrated their respect at the observances.
Police and firemen were quick to assemble in front of the U.S. Embassy in the days following the attacks. Many of those who died in New York were firemen.
The U.S. Embassy said that the 8:15 a.m. ceremony Sunday would commemorate the victims of the attack and also others who have been victims around the world. The ceremony also will recognize the importance of the Fuerza Pública, the Cuerpo de Bomberos and the Cruz Roja who are called upon during disasters in Costa Rica, the embassy said.
The monument is by Florida sculptor Roland Hockett, who said he used copper instead of steel so that the work would endure longer. It was finally inaugurated Sept. 11, 2004. It stands on a hill overlooking the Centro Cultural Costarricense Norteamericano in Sabana Norte.
Expected guests include Mario Zamora Codero, the security minister, and Johnny Araya, mayor of San José. Also there will be U.S. Ambassador Anne S. Andrew, the embassy said.