Father Dennis Zehren struggled to hold back tears as he addressed his Minneapolis congregation, drawing on Jesus' parable of humility to reflect the community's grief afterthis week's deadly shooting. "Jesus says… sit with me in this low place," the Annunciation Catholic Church pastor told the packed auditorium on Saturday, just days after a shooter fired through the church's stained-glass windows at students in prayer. The Mass, held in the school auditorium just steps away from the parish's now-closed sanctuary, marked the first such gathering for the congregation since the attack. The church that three days before was filled with excited students and watchful teachers at the start of a new school year is now a crime scene. "This is not our normal seat, this is not where we usually gather, this is not our usual worship place," Zehren said as he joined his parishioners in turning to prayer, music and shared silence in a room overflowing with both people and grief. The shooting left two children dead — 8-year-old Fletcher Merkel and 10-year-old Harper Moyski — and wounded 18 others, including 15 students and three elderly parishioners. "It will never be the same, but it's a call to begin again," Zehren said. Outside the church, a memorial of flowers, stuffed animals and signs grew. A note from Fletcher's mother read, "I love you always and forever." Zehren said the tragedy has brought an outpouring of support from around the world. "We will be sitting in a different pew for a long time to come," he said, urging parishioners to seek mental health resources as they begin to heal from something "far beyond what we've experienced before." Police identified the now-deceased shooter as a 23-year-old former Annunciation student whose mother once worked at the parish. Investigators are still searching for a motive. With classes suspended, children have already lost cherished traditions such as Spirit Day and a butterfly release. The sanctuary is now missing the familiar sounds of hymns and the children's voices that once echoed through its halls. Minneapolis Police Chief Brian O'Hara described the attack as "slaughter," noting the shooter was "standing outside of the building firing through very narrow church windows on the level where they would line up with the pews." Ten-year old Weston Halsne recalled he was two seats away from the windows when the shots rang out and his friend dove on top of him, saving him but getting hit in the back: "He's really brave." Outside the church, Jesse Merkel, Fletcher's father, mourned the loss of his son. "We will never be allowed to hold him, talk to him, play with him, and watch him grow into the wonderful young man he was on the path to becoming," he said. "While the hole in our hearts and lives will never be filled, I hope that in time our family can find healing," Merkel said, holding back tears. He asked the community to "remember Fletcher for the person he was" – a boy who loved his family and friends, "fishing, cooking, and any sport that he was allowed to play," and "not the act that ended his life." Harper Moyski's parents described their daughter as "bright, joyful, and deeply loved," urging leaders to take meaningful action to address gun violence and the "mental health crisis in this country." "Change is possible, and it is necessary—so that Harper's story does not become yet another in a long line of tragedies," they said. "As a family, we are shattered, and words cannot capture the depth of our pain." Among the wounded, Endre Gunter, 13, survived surgery after being shot twice. "Yet we still have our child. Unlike others, we are blessed to hold onto him," said Endre's mother, Danielle Gunter. He showed "strength and faith beyond his years," his aunt said, as he recovers surrounded by loved ones. Community members in Minneapolis say they are finding ways to support victims of the senseless tragedy, but that online fundraisers are simply not enough, reportedCNN affiliate WCCO. Residents are supporting victims by tying blue and green ribbons on street poles and distributing yard signs reading, "Our hearts are with Annunciation." Linda Nucci, who organized the signs, said, "You want to take that energy or that grief and figure out what you can do with it." "When anything like this happens, you just want to feel useful. You want to take that energy or that grief or that, you know, uncomfortability and figure out what can you do with it," Nucci said. Sarah Henning, another community member leading memorial efforts across the city, told the outlet that 300 volunteers helped her group tie nearly 3,000 ribbons on street poles and trees. "We were able to get ribbons into Fletcher's neighborhood yesterday, and we've had several neighbors reach out about what that meant," she told WCCO. "I want them to experience unbelievable love after unbelievable tragedy," Henning said. "That's why we're doing it." For more CNN news and newsletters create an account atCNN.com