The US estimated that taking these three Islands would take a lot of firepower and personnel and sent a fleet of 535 warships and an invasion force of 127,000 service members. The Battle of Saipan began on June 15, 1944, and lasted for 24 days, resulting in 30,000 Japanese soldiers being killed along with all four of their commanders and 480 of their aircraft being destroyed. The US forces lost 3,000 service members and over 10,000 wounded.
So many US personnel were lost on Saipan that after the war, the US dedicated the 400-acre American Memorial Park, which is adjacent to the central city of Garapan. The National Park Service and its non-profit Pacific Historic Parks run and help maintain the Park for the citizens of Saipan.