raw sewerage in basement

My building had a sewer pipe burst in the basement that became flooded with raw sewage. The managment requires tenants use the service entrance's basement to exit the building with their dogs, and also the laundry room is there. This leak went on for quite awhile with the stench of feces and staff not acknowledging there was a problem until it became unmanageable with flooding and the basement was off limits. I was ubnder the impression that the NYC Board of Health requires a licensed professional clean up this catastrophe. The landlord choose to have their staff clean up the mess. Isn't this against the law?