What if the stairs on the second floor of the duplex building are blocked by neighbors?

Complain to the property company or report to the fire department of the public security organ. After the stairs on the second floor of the duplex building are closed by neighbors, it will affect the normal use of individual houses and lead to fire hazards. In this case, you can choose to complain to the property company, and the property will come forward to solve it, and the closed area will be demolished. If the property company can't manage it, it can also report to the fire department of the public security organ, which will be dismantled by firefighters and demand compensation from the other party. In this case, the owner must choose a formal way to solve it, and can't have a direct conflict with the other party, nor can it be demolished without permission, so as not to cause unnecessary losses and troubles.