The archbishop of Denver has voiced deep sadness and promised prayers for the victims of a shooting at a Colorado high school on the afternoon of Dec. 13.

"Today, we offer our prayers and profound sympathy for all those involved in the shooting at Arapahoe High School," said Archbishop Samuel J. Aquila in a statement.

"I am saddened by this tragedy, which has been repeated too often in recent memory," he said. "My heart goes out to the victims and their families, and my prayers, as well as those of the faithful in the Archdiocese of Denver, are with them."

According to police reports, a gunman walked into Arapahoe High School – located in the southern Denver suburb of Centennial – and tried unsuccessfully to confront a specific teacher, who learned of the situation and left the building. The gunman reportedly injured three people before apparently killing himself.

One victim was reported to be in serious condition, while the two others were listed as being in good condition.

Some students fled the school during the shooting, while others stayed in locked-down classrooms.

"I was scared and shaking," one student told the Denver Post.

Police slowly cleared the school, searching students as they were allowed to leave. Many distressed parents rushed to the school in an effort to find their children.

Arapahoe High School has approximately 2,100 students. It is about eight miles from Columbine High School, the scene of a deadly shooting in 1999 that left 15 dead, including two gunmen. Colorado was also the scene of the July 2012 shootings at a movie theater in the east suburb of Aurora, which killed 12 and wounded dozens more.

The Dec. 13 shooting took place just a day before the one-year anniversary of the devastating shooting at Sandy Hook Elementary School in Newton, Conn., in which a gunman killed 20 children and six adult staff members, as well as his mother and himself.

As news of the Arapahoe High School shooting broke, many other schools in the Denver area, including Catholic schools, went into secure lockdown. No other incidents have been reported.

Colorado Gov. John Hickenlooper called the shooting "an unspeakable horror" and "something no child, no family should have to endure."

Archbishop Aquila voiced gratitude that "first responders, school teachers and administrators were able to react with effective lockdown procedures."

"Unfortunately for all of us, however, we are once again confronted with the effects of a culture that has little respect for life and is desperately in need of the healing that only God can give."

"As we prepare our hearts for the birth of Christ, let us keep our youth in our prayers," he said. "In these last weeks of Advent, let us pray that as a culture we find the path to peace, which begins with accepting God's mercy and forgiveness."