In the time of Titanic, American immigration laws required that locked barriers be installed on all emigrant ships to isolate the steerage, in order to control the spread of disease normally brought over by the poorer elements of society. Any ship not fitted with barriers (or found to not be using them in accordance with the law), risked being held at Quarantine Station (just inside the Narrows on the Staten Island side), unable to discharge any passengers until the American Health Officers completed the timely process of personally checking each soul on board (normally, they only checked Third Class passengers) to verify that the ship was free of disease. In extreme cases, all passengers might be disembarked on Fire Island, where they would be held in quarantine for forty days before they could complete their journey to New York. This was costly to the Line and impacted negatively on the ship's reputation. Most steamship companies, including White Star, ensured that their ships complied fully with these regulations.