Columbine's library remains sealed off as investigators continue to gather evidence from the room RELATED VIDEO Fresh paint and new carpet can't erase the memories at Columbine High School. CNN's Charles Zewe talks with one family who lost a son there. (June 15) Windows Media 28K 80K

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School shootings

June 15, 1999
Web posted at: 7:58 p.m. EDT (2358 GMT)

In this story: New security measures Library remains sealed off RELATED STORIES, SITES

LITTLETON, Colorado (CNN) -- The mother of a shooting victim accompanied reporters Tuesday on their first look inside Columbine High School since the April 20 massacre that killed 15 people and wounded more than 20.

Near bullet holes marking the spot where Daniel Rohrbough was killed, his mother, Sue Petrone, embraced her husband, Rich, and wiped away tears.

"I envision him coming out of the room with his friends," she said. "They came out of the door right there just laughing and having a good time ... and then in the next instant he was dead."

Construction crews are working to renovate heavily damaged areas of the school where students Eric Harris and Dylan Klebold went on a killing spree with guns and bombs before shooting themselves to death.

The blood-stained carpeting has been ripped away. But an estimated 900 to 1,000 bullet and shrapnel holes are left in the charred walls and ceilings and many window panes are shattered.

New security measures

School officials said the attack damaged about 23,000 square feet of the school, but they declined to estimate the cost of repairs.

Blood-stained carpet, top, was removed from the stairs, but bullet holes remain in a door jamb, bottom

Other changes, such as the sound of the fire alarm, are being made to try to lessen the psychological impact on students when they return for a new school year August 16.

"The tone of the fire alarm was something that would really, really have an emotional effect upon them," said George Latuda, an official with the Jefferson County school system.

Psychologists warned that the alarm, which sounded during the rampage, could cause students to experience flashbacks.

Security is also being upgraded, including the addition of more surveillance cameras inside and outside of the building.

Library remains sealed off

But Rich Petrone said efforts to prevent similar school attacks should begin at home.

"You can have all the security in the world, but if your kids don't have any values of life, value of human life at all, it wouldn't have prevented it," he said.

The library, where most of the victims were killed, was sealed off. It will remain a crime scene for two more weeks as laboratory technicians complete tests on evidence taken from the room.

Sue Petrone said that Columbine parents believe the library should never be re-opened. She suggested that a front office space be converted into a new library or another wing be added to the school.

The aim of the renovations is to remove all physical traces of the attack before the students return.

"You know, you have to do it with real reverence and none of us have ever been through anything like this," said Jack Swanzy, the project's architect.

Correspondent Charles Zewe contributed to this report.