I live near by Eric Harris's residence.

On Saturday, April 10, 1999 - at about 10:00 am, I woke up and heard the sounds of hammering in Eric's house.

No glass shattering or anything else. Just the sound of a hammer smashing something and being used, over and over again.

The worst sound effects I heard otherwise from his house, would be the occasional firework going off. That would be about it.