"As Catholics, we are called to pray for the living and the dead as one of our spiritual works of mercy," said Gina Horton, and English teacher and leader of campus ministry at the school.
A gunman killed 28 people at Sandy Hook, including 20 children, then committed suicide. Another person was found dead at a second location, leaving the death toll at 28.
Law enforcement officials said 20-year-old Adam Lanza was the gunman. Lanza was said to be the son of a teacher, Nancy Lanza, who was presumed dead.
Authorities also were questioning Lanza's 24-year-old brother, Ryan, a Hoboken, N.J. resident.
"Comfort the families in their loss and sorrow," Horton prayed for the victims. "Be their refuge and their strength, oh Lord, and lift them from the depths of grief into the peace and light of your presence."
The massacre weighed heavily on school administrators and staff.
"I can't imagine what those parents are going through," said Jim Brennan, president of Aquinas.
Brennan said safety is always a top concern at the school, and faculty and staff routinely undergo training for emergencies.
"You go through all sorts of scenarios and yet you look at this and it's hard to prepare our kids for this because (Lanza) was a relative (of a teacher)," Brennan said. "I have a son who graduated last year. If he came in to visit me, people wouldn't stop him."
Enrollment at Aquinas is 370.
Brennan said safety measures at the campus include an alarm system, routine department meetings and code words for emergencies that call for the school to be locked down.
Aquinas is protected by a wrought-iron fence.
"That being said, if a radical person decides to come over the fence, it would be hard to do something about it," Brennan said. "You can't prepare for everything. You just give it your best shot and hope people act in a reasonable way."
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