Check your insurance policy. I'm sure there is liability there.
More than 1 million people went to emergency departments for trampoline-related injuries between 2002 and 2011, with nearly 300,000 of those injuries involving broken bones, according to a new study.
And these injuries don’t come cheap — the Journal of Pediatric Orthopaedics study showed that the total emergency department expenses for them was $1 billion, and more than $400 million for fractures specifically.
What you really care about is making sure that
they are taking the risk so just create a lease addendum that gives them permission and makes them assume liability. Everyone wins and you don't feel like a jerk for taking a trampoline away from kids.