New tenant injured with shower door

New landlord here, just took over property with existing tenants. Few days after closing, visited property with contractor to get estimate to address some of the items that came up on inspection report. 
One of the units has a glass shower door that doesn't roll. Friday we visited the unit.- shower door needs new rollers but not broken. 
Saturday morning, tenants messages saying that her shower door doesn't close very well and if I can help with that. 
I message back tenant asking for more information about the door. No response from tenant
Monday AM- tenant sends pictures of foot with blood, saying that door fell on her last night and she has glass on her foot. 
Checked in with tenants,they seem ok. I asked for video of the broken door so I can figure out who to send out there.
How to deal with repair? 
Remove glass door completely and put a shower rod and curtain because it will take some time to replace this glass door?
Who should pay for the repair? Tenant or landlord? We don't know who is responsible for it, we didn't inspect the property when this tenant started lease. We got ownership 6 months into their lease. 
Please advise whats the safest, easiest troubleshooting here?