The terrorist attack of Sept. 11, 2001 is and should be as engraved on the memories of this generation of Americans as the Dec. 8, 1941 sneak attack on Pearl Harbor was for an older generation.

This year Sept. 11 has special significance because it is the 10th anniversary of the killing of so many innocent people, and because it is a Sunday, a day on which many churches will commemorate it during their liturgies.

At St. Helena in Blue Bell, the parish, in conjunction with the St. Helena Council Knights of Columbus, will hold its fifth annual Blue Mass at 11 a.m. that day with Montgomery County area police, firefighters and emergency medical responders, neighboring congregations and public officials as invited guests.

Last year the event drew 250 attendees; this year it will probably be larger.

“Whitpain Township will have a 1 p.m. dedication of a monument to mark Sept. 11,” said Msgr. Joseph J. Nicolo, pastor of St. Helena’s and chaplain for the Knights of Columbus. Because of the township dedication those who attend the parish Mass will process from the church to the township hall, he explained, and the Knights, who normally follow the parish Memorial Mass by hosting refreshments in St. Helena’s Empress Room, will provide refreshments in the township hall.

At Our Lady of Grace Penndel, Sept. 11 will be marked by a 7 p.m. ecumenical prayer service to honor all first responders in the community. Those who attend are invited to wear red, white or blue, to signify their support.

“We lost one member of our parish in the twin towers,” said Father James R. DeGrassa, parochial vicar at Our Lady of Grace. “We have invited all of the neighboring churches and the scouts.”

Of special note, the parish youth choir that will sing at the service will be in New York on Sept. 10 to participate in a special service for the anniversary at St. Patrick’s Cathedral.

This year Sept. 11 has special significance because it is the 10th anniversary of the killing of so many innocent people, and because it is a Sunday.

St. Joseph Church in Ambler will also have a special commemorative Mass on Sept. 11 at 11 a.m. to honor the victims, their families and all who responded on 9/11. Firefighters, auxiliaries, police, staff, emergency medical technicians, dispatchers, armed service members, active and reserve, and veterans and their families are invited. Refreshments will follow in Heritage Hall following the Mass.

St. Cecilia Parish in Philadelphia will also honor police, firefighters and veterans at the 11 a.m. Mass. The Boy Scouts will also participate in the procession.

Yardley-Newtown is an area where a number of the victims of Sept. 11 lived, and St. Andrew Parish in Newtown will mark the sad anniversary with several events.

Members of the community have made 2,973 candles for the Garden of Reflection of Lower Makefield which is located at 1950 Woodside Road, Yardley. The candles will be blessed by St. Andrew’s pastor, Msgr. Michael Picard, at a 7:30 p.m. ceremony on Sept. 10, according to parish development director Jennifer McDonald.

On Sept. 11, Msgr. Picard will participate at an 8:30 a.m. remembrance ceremony in the Garden of Reflection, and all parishioners are encouraged to attend. Prayers for the fallen will be added to the Prayer of the Faithful at the weekend Masses. On Sept. 9, the children of St. Andrew School will participate in a special ceremony for the anniversary and the religious education students will also have prayers at their sessions.

“We wish events like this were not necessary,” McDonald said, “but it is the right thing to do.”

Also, among the many other parishes that will mark Sept. 11 at their services are St. Luke the Evangelist in Glenside and St. Leo in Philadelphia.