Where did the greatest number of US casualties occur Tarawa Iwo Jima or Omaha or was there a greater number somewhere else?
The answer to this question depends on a few other factors. Tarawa lasted 76 hours, start to finish. 724 Navy and 950 Marines died directly, with another 3 Navy and 34 Marines dying of wounds later. Iwo Jima lasted 38 days, with 934 Navy and 4907 Marines killed outright, and another 48 Navy and 614 Marines dying of wounds later. Source: US Navy Bureau of Medicine, History of the Medical Dept in WWII Vol 3. Ground casualties at Omaha on the first day come in at around 1500 dead, most suffered by the US 1st and US 29th Divisions. The airborne operations behind Omaha were very costly as well, but the 238 reported Airborne deaths are not broken out to detail which beach was supported. Source: http://www.ddaymuseum.co.uk/faq.htm It's important to note that only deaths have been factored in here. The term casualty normally includes wounded. The data is available but not necessarily enlightening. An infantryman wounded on Omaha who is killed breaking out of St. Lo fits which category? Over time, it's possible that Monte Cassino (in Italy) or the Huergen Forest (in Germany) produced more casualties than the battles you mentioned.