WASHINGTON, Jan. 23, 2013 /PRNewswire-USNewswire/ -- Over 10,000 worshippers, many of them youth from schools around the nation, are expected to gather in the Basilica of the National Shrine of the Immaculate Conception to pray for an end to abortion at the Opening Mass of the National Prayer Vigil for Life, Thursday, January 24, at 6:30 p.m., the eve of the annual March for Life. The vigil coincides with the 40 th anniversary of the Supreme Court's Roe v. Wade decision on January 22, 1973, which legalized abortion nationwide. Since the decision was handed down, an estimated 55 million abortions have been legally performed in the United States. "Marking the anniversary of the Roe decision each year could be disheartening in light of the lives lost and the lives shattered by abortion," said Susan Wills, assistant director of the U.S. Conference of Catholic Bishops Secretariat of Pro-Life Activities, "but this Mass and events this week are also a time to pray with faith and hope in God's mercy." "The commitment and energy of hundreds of thousands of young people who are here to pray and to march on behalf of unborn children and grieving post-abortive mothers is proof that the pro-life movement is alive and growing and stronger than ever," she added. Cardinal Sean O'Malley of Boston, Chairman of the U.S. Bishops' Committee on Pro-Life Activities, will be the principal celebrant and homilist at the Vigil Mass, concelebrated by fellow cardinals and many of the nation's bishops and priests. Following the Opening Mass, the Vigil will continue in the Crypt Church of the Basilica with confessions, a National Rosary for Life, Night Prayer according to the Byzantine Rite, and holy hours led by seminarians from across the country from midnight until 6:00 a.m. That same evening, The Catholic University of America will host more than 1,200 pilgrims overnight. On Friday, January 25, the Basilica will host Morning Prayer at 6:30 a.m. in the Crypt Church and the Closing Mass at 7:30 a.m. in the Great Upper Church. Bishop Kevin J. Farrell of Dallas will be the principal celebrant and homilist. The National Prayer Vigil for Life is co-sponsored by the Secretariat of Pro-Life Activities of the United States Conference of Catholic Bishops (USCCB), the Basilica of the National Shrine of the Immaculate Conception, and The Catholic University of America. Media are welcome to attend the Mass and speak with and interview pilgrims.