"Something big and heavy just fell on it"

Yesterday late afternoon Jason, James and I were sitting in the living room when Bekah came in to inform us that "something big and heavy just fell on Zach's bed". Lets back up a bit to set the stage for you....James moved in with us a few weeks back and we moved Bekah into the boys room. Bekah is on the top bunk, Bobby on the bottom and Zach in his new toddler bed. We are going to paint in the near future so no pictures or shelves have been put on the walls just yet. Now back to Bekah's comment "something big and heavy just fell on it"...at the time of the crime Bekah and Bobby were playing in their bedroom and Zach was sitting on the couch with Jason. Now I am not a detective or anything, but I used my super mom skills and sorted out the facts...1. older kids in bedroom alone, 2 no heavy objects in said room except older kids, 3. one of the house rules no jumping on beds. After carefully examining the facts (and the guilty look on older kids faces) I came to the conclusion that the "something big and heavy" was in fact my older two children! When they realized they were busted they confessed to jumping on Zachs bed. Not only did they jump on his bed, they broke all but 2 of the boards used to hold his mattress in place! Zach ended up sleeping on his mattress on the floor last night and the judge( Mom and Dad) is still coming up wih the sentence for the two convicted liers! Any suggestions?