Racist, sexist graffiti in the new World Trade Center bathrooms.

Port Authority police are now investigating. Who wrote these things? The construction workers?

“Such slurs are offensive and have no place at the World Trade Center site or elsewhere,” PA spokeswoman Lisa MacSpadden said. “The Port Authority has zero tolerance for those who demonstrate intolerance.”

The construction company said it has an anti-vandalism policy which it would "reiterate" to its crews.

Hardhats who toil on the site said the foul writing on the walls is a fact of life at all job sites — and there’s not much anyone can do about it.

Black construction workers, victims of some of the most repugnant scrawls, were furious but said they don’t dare complain when they see the N-word.

“You ask any black person on the job, and they’ll say, ‘What can you do about it?’ ” said an outraged Tyson Patterson, 35, of the Bronx. “You talk and you get fired. I have to be political and pretend it doesn’t bother me.”