A Bronx community board is fighting back against landlords and tenants who create unsafe living conditions with illegally converted housing.

The Waterbury LaSalle Community Association plans to write the mayor about the problem. The conversions, which increase the number of apartments in buildings, create walls and obstacles. Those obstacles can have fatal consequences in the event of a fire.

The Department of Buildings says tenants can check its Web site for layout information to find out whether their housing is illegal.