Catholic dioceses in New York, Washington, D.C., and in many other locations across the country will soon be holding Masses and other ceremonies in memory of those killed in the September 11, 2001 terrorist attacks on the World Trade Center and Pentagon.

Many of the liturgical ceremonies will also honor the memory or current service of all the nation's police, firefighters, and emergency personnel.

A Blue Mass is traditionally held to honor law enforcement officers, particularly those who have died  in the line of duty or otherwise demonstrated a heroic commitment to their work for the community. Fr. Thomas Dade, a Washington, D.C. priest who founded the Catholic Police and Firemen's Society, began the tradition in 1934 of celebrating an annual Mass for emergency workers, who always attend in uniform.

Fr. Dade's tradition has since spread throughout the nation. Because hundreds of police and rescue workers were killed at the World Trade Center on September 11, the date is becoming an increasingly common one on which to celebrate the Blue Mass.

The Roman Catholic Diocese of Rochester in New York will hold a Mass to “pray in a special way for all firefighters and first responders, and for all those who lost their lives at the World Trade Center tragedy nine years ago,” on September 11, 2010 at 4 p.m., with Bishop Matthew Clark as the celebrant.

A concert in honor of the fallen will be held at Saint Patrick's Cathedral in New York City at 7 p.m. on the same day.

Although Archbishop Donald Wuerl already celebrated a Blue Mass earlier this year at St. Patrick Catholic Church in Washington, D.C., a public memorial ceremony will be held at the Catholic University of America on September 10,  including a reading of the names of all 2,974 victims of the 9/11 attacks. The ceremony will begin at 3:15 p.m. and be followed by a candlelit vigil at 5:30 p.m.

John Miller, associate director of the Archdiocese of Denver's Office of Liturgy, described the universal appreciation of the annual Blue Mass in his community. “We have both Catholics and non-Catholics attend this event every year,” he said.

The annual ceremony is “a wonderful opportunity for the Church –and the entire community—to come together and recognize our First Responders,” Miller reflected. “We thank God for the sacrifices they make, every day, for the protection of our well-being.”

Denver's Auxilary Bishop James Conley will be the celebrant at his archdiocese's Blue Mass, to be held at the Cathedral Basilica of the Immaculate Conception at 4:30 p.m. on Saturday, September 11.