Tenant Arguments in Duplex

[Donald DiBuono]

First time landlord. I own a duplex and both tenants pay on time and I like them both individually (not that it matters). The two tenants are not getting along. I have contacted them both to try and work it out. They do not want to have a sit down and have it mediated. Tenant 1 wants to be left alone and wants to do laundry Sunday and Wednesday. Tenant 2 sometimes will bring mail upstairs and seems to be always doing laundry. Recently they had a fight that was very verbal and almost physical. Im at a loss what to do because both tenants are contacting me and giving me two sides to the story. Any advice on how to better help the tensions?