HOUSTON, Texas — In response to the May 18 school shooting at a Houston-area high school, Cardinal Daniel N. DiNardo of Galveston-Houston said the archdiocesan community would “unite to support and offer healing to those affected.”

“As a society, we must strive for a way to end such acts of senseless gun violence in our schools and communities,” he added in a May 18 statement.

The cardinal, who is also the president of the U.S. bishops’ conference, said he was “deeply saddened” and that his prayer and the prayers of Catholics in the archdiocese are with the “victims and families of those killed and injured in this horrific tragedy.”

The school shooting, occurring just three months after the shooting in Parkland, Florida, took place when a male shooter opened fire at a Santa Fe High School the morning of May 18 killing 10 people, most of them students. A suspect taken into custody was identified as 17-year old Dimitrios Pagourtzis and another person of interest also was detained and questioned.

Explosive devices also were found at the school and off campus.

Pagourtzis had played football on the school’s junior varsity squad and danced as part of a church group. Those who know him expressed shock Friday that he might be involved in the killings.

The shooting was the deadliest in Texas since a gunman attacked a rural church late last year, killing more than two dozen people.

“We experienced an unthinkable tragedy at our high school this morning,” Superintendent Leigh Wall said in a message posted to Facebook.

“As soon as the alarms went off, everybody just started running outside,” 10th-grader Dakota Shrader told reporters, “and next thing you know everybody looks, and you hear boom, boom, boom, and I just ran as fast as I could to the nearest floor so I could hide, and I called my mom.”

Another student told CBS News he ran behind some trees, heard more shots, jumped a fence and ran to a car wash. He said he saw firefighters treat a girl who had a bandage around her knee and may have been shot.

Father Stelios Sitaras of Assumption of the Virgin Mary Greek Orthodox Church in Galveston, Texas, told The Associated Press he met Pagourtzis when the young man danced with a group as part of an annual festival in October. He said the Pagourtzises are members of a nearby parish.

Sitaras said he had never heard of the teen being in any sort of trouble.

“He is a quiet boy,” the priest said. “You would never think he would do anything like this.”

Crux staff contributed to this report. This report also incorporated material from the Associated Press.