By Michael Erman NEW YORK, Sept 20 (Reuters) - New York City's health care system is not prepared for a major disaster such as a large-scale attack, hurricane or pandemic, health care and disaster planning experts said. The city, struck in the Sept. 11 attacks and a world financial center, is vulnerable due to underfunding and a lack of understanding of the possible complexities of a crisis, officials from city hospitals and emergency services said this week at a conference on disaster preparedness. Disaster preparedness in the United States has been a leading preoccupation of U.S. authorities since the Sept. 11 attacks. That concern was heightened after Hurricane Katrina struck New Orleans and other parts of the U.S. Gulf Coast in 2005, killing more than 1,400 people and revealing gaping holes in local and federal planning. "We have no idea what a prepared New York is. What we're doing now is random acts of preparedness that all together don't really amount to an appropriate safety net," said Irwin Redlener, director of the National Center for Disaster Preparedness at Columbia University's Mailman School of Public Health. "We're in a very, very bad place." The consensus at Tuesday's conference was that New York was more prepared than New Orleans had been before Katrina hit. The experts said many city agencies such as New York's police department, fire department, and Office of Emergency Management are among the best in the country. Still, they said the city's size -- New York City has a population of more than 8 million -- and urban density and diversity make additional planning necessary. Brian O'Neill, who heads emergency services for the North Shore - Long Island Jewish Health System, said the city's emergency services have the potential to move large numbers of people injured in a catastrophe, but not necessarily the hospital capacity to deal with them. "We don't have 20,000 open beds ... for hospitals to absorb that," O'Neill said. "We would have to rely, at that point in time, for long-term solutions from the federal government." Columbia's Redlener said hospitals would be immediately overwhelmed in such a situation and the number of deaths would balloon. HURRICANE WORRIES A hurricane could also cause chaos. Before Katrina, the Red Cross estimated that it would have to evacuate 1 million people and shelter 250,000 if a major hurricane hit New York. Now it believes it would have to evacuate 3 million New Yorkers, 600,000 of whom would need shelter, according to Scott Graham, Chief Response Officer for the American Red Cross in Greater New York. The city is better prepared for a natural outbreak of infectious disease because federal institutions now closely track diseases and can quickly isolate them. Nevertheless, such an outbreak could still fill city hospitals and leave the city's relief agencies strapped. Bruce Logan, Chief of New York Downtown Hospital's Department of Medicine, said he was unable to get federal funding for an expansion of the hospital's emergency room, despite being four blocks away from Ground Zero where the World Trade Center's twin towers were destroyed on Sept. 11 and the first hospital to respond to the attacks. "We're in the financial capital of the world ... I see that emergency room as an element of our national defense," Logan said. "Unfortunately, I can't get our government officials -- especially the state and federal ones -- to see it the same way."