"The school is in panic"
The words above are part of the 911 call made by Patti Nielson who was in the library at the time of the shooting. At around 11 A.M the shooters, Eric Harris, and Dylan Klebold walked into the school. They arrived in two separate cars, both filled with bombs and ammunition. The two shooters both knew that this was the time of the busiest lunch. With approximately 500 students in the cafeteria, they would choose to attack now. So, they went into the cafeteria with a bag full of pipe bombs, carbon dioxide bombs, and propane bombs and waited for it to detonate. They waited outside the cafeteria and planned to pick off any kid who had escaped the cafeteria. When none of the bombs detonated the two gunmen went into the school with their fire arms. They headed up into the library where most of the shooting took place. That was were most of the deaths occurred.