Because of the high death rates on the transatlantic voyages, many of the vessels that carried Irish Famine refugees to the Americas were simply known as "coffin ships." During the Famine's worst year - Black 1847 - approximately 20,000 out of 100,000 emigrants perished at sea. Most were carried away by the diseases that ran freely in the reeking holds of the ship. Dr. J. CUSTIS, a physician who traveled aboard six Famine ships, wrote that although he had witnessed the devastation of the Famine in the workhouses of Ireland, "it was not half so shocking as what I subsequently witnessed on board the very first emigrant ship I ever sailed on." As one priest observed, "it would be better to spend one's entire life in a hospital than to spend just a few hours in the hold of one of these vessels." One notable exception to this saga of terrible suffering, is the story of the "Jeanie Johnston." Incredibly, it never lost a passenger or crew member, either to disease or accident at sea, during its many voyages between 1848 and 1858 from Tralee, Co. Kerry (an area that eventually lost half its population during the Famine) to ports in America and Canada. Most likely this was due to its humane captain and the owner's decision (rare among Famine-era ships) to have a doctor on board. A full-size replica of the "Jeanie Johnston" completed in 2001 in Blennerville near Tralee, Co. Kerry, now serves as a working sailing vessel and floating museum, per Edward T. O'Donnell, "1001 Things Everyone Should Know about Irish American History," 2002. Even if Irish Famine refugees managed to survive the perilous 25 to 50 day voyage to North America, thousands perished in port hospitals and quarantine stations. The mot notorious of the latter was Grosse Ille, a quarantine station and makeshift hospital on an island in the St. Lawrence River near Quebec. Beginning in the spring of 1847, thousands of sick and weakened Famine immigrants began to arrive, and by the end of the year more than 17,000 of them lay buried in mass graves despite care given by people of different faiths who put their own lives in peril to tend to the ill. Per O'Donnell, disease was not the only threat to life aboard the coffin ships. Many Irish emigrants died in the more than 60 shipwrecks which occurred during the Famine year. The "Vermouth," for example, foundered in 1847 just off the coast of Scotland, taking with it all but three of its 251 passengers. A few months later, the "St. John" fared only slightly better, losing at least 99 passengers when it smashed on the rocks near Cohasset, MA. Hundreds came to see the wreck, including Henry David THOREAU. "I sought many marble feet and matted heads a the cloths were raised," he wrote, "and one livid, swollen and mangled body of a drowned girl, who probably had intended to go out to (domestic) service in some American family." On top of disease and disaster, immigrants faced still a third threat - abuse and mistreatment by callous crewmen. This took many forms, from overcrowding to violence, and occurred mainly on the shorter trips from Ireland to England. The worst incident occurred aboard the steamer "Londonderry" in the winter of 1848. Loaded with cargo and 174 immigrant passengers, the shop encountered a storm just off the coast of Donegal. Though most of the passengers were expected to make the journey on deck, the captain ordered them herded into one of the ship's three cabins. The next morning brought to light a horrifying scene -- 31 women, 23 men and 18 children had been crushed or suffocated to death. The jury that found the captain and crew guilty of manslaughter noted that the cattle aboard the ship had received far more humane treatment than the people.