Garage Door Broke after Crushing Bike

[Mariam Arghandewal Safi]

Hello everyone! My name is Mariam. My tenant's son closed the garage door on his bike and broke the garage door. Do I have to bite the bullet and take on the cost or is this the tenant's responsibility? 

The tenant thinks the door should have stopped and retracted.  I think the sensors which are on each side of the door probably shot through the spokes of the wheel (see picture) which is not a solid object and hence the door didn't retract. The tenants claim "The failed sensor never relayed to the garage door and it kept trying to close itself unlit it stopped. It had so much force to it that it crushed the top of the garage door. I’ve never seen anything like this before." If you look at the attached pictures the bike isn't tilted, doesn't seem to have fallen over. The position of the bike to me indicates that the garage door closed on it and stoped. I doesn't look like it kept trying to close itself until it stoped.If that was the case, the force would have caused the bike to fall over or at least tilt to one side. What do I do? This tenant has been a very problematic tenant. I've always given them the benefit of the doubt but I am just sick of all theses "accidents" which keep costing me money. I'd love to hear any input. 

Best