Young Students Recall Nightmare of School Shooting in Madison, Wisconsin

Terrified students at the Wisconsin school where 15-year-old Natalie Rupnow opened fire are now speaking out, recalling the fear they felt as the tragic event unfolded.

Check out the video -- one little boy bravely told CNN several people started crying during the chaos at Abundant Life Christian School in Madison, WI, on Monday as they had to wait for the police to arrive ... before being escorted out of the school to the church.

Heartbreakingly, the boy added that he was super scared and just wanted to know why the shooter did what she did.

One little girl also shared her experience, recalling how she saw an injured teacher screaming for help -- which made her "really scared" and "really sad."

No child should ever have to endure such terror ... and the situation hit even harder knowing that it was a brave 2nd-grader who dialed 911 around 11 AM Monday to report the school shooting.

The shooter, identified as a pupil at the school, killed a teen student and a teacher, leaving 6 others injured -- 2 in critical condition.

According to police, she died from a self-inflicted gunshot wound. Detectives are investigating what motivated Rupnow to carry out the horrific attack.