Neighbor Has Built A Fence In Front Of My Fence, Blocking The Exit

Location: North Shore, Massachusetts

Multi-family home, two exits, front and back. 1st/2nd floor can exit both the front and back, 3rd floor only the back, this will be important. All tenants are renters

So about a year ago my neighbor decided he needed to screw the gate to our fence shut because from the sidewalk you have to cross his parking spot and the FedEx/Amazon folks were using it. This was the main exit for the 3rd floor since the house opens to that exit. Now they have to walk a narrow fence line along the side of the house to exit the building.

I argued that this was a fire hazard, since a major egress was being blocked, and the only exit would be running down a 2ft wide alley next to a house that is potentially on fire. That seemed to convince the owners to remove the screws from the fence. We also agreed that the 3rd floor wouldn’t use the gate unless there was an emergency

Now a year later he has decided for some reason to build another fence in front of ours. Seems he gets a stick up his ass about once a year and just decides to take it out on his neighbor? I honestly have no idea what caused this, when I asked him about it he said it had nothing to do with us, and it’s because someone keeps keying his car. But he said he wouldn’t remove it.

Technically the fence is ours, it’s a foot inside our property line, what he has done is build this structure a foot out BUT attached it to our fence with boards. I could remove the boards, but I don’t want to escalate things unless through legal means or by the owners

Again, I feel like this is a major fire hazard. The owners of the building say they’re not going to do anything about it. I’m curious what my options are at this point? I feel like if I report it something will have to be done. I would rather the structure be taken down, but I’m afraid that the owners of the building bare the main responsibility for having an egress point and I dont want retaliation. Curious what my options are