Do You Think My College Students Tenants Busted this Floor Joist?

[Will Gaston]

All:

My handyman just called me and said that a floor joist was split underneath one of my college student rentals. Five guys live there and had friends over for the Super Bowl on Sunday night. They claim it was only "20-30 people" and they weren't jumping. They did not report this until Tuesday afternoon. I imagine this is going to be a several thousand dollar fix (3k-5k?) so I would like to try and collect. They, of course, will deny that they've done anything wrong based on my experience. 

Can anybody provide any insight on what you think happened based on the pictures below? The property was built in 1965 if that makes a difference. 

Naturally I am biased but do not believe them. However, in a he said/she said situation with college kids and their grizzly bear parents things can get heated and nasty very quickly so I want to know what kind of case I have here.

I will have dealt and seen a lot over all the years I have rented to students but this is a first for me.