At the beginning of August 1942, Rosecrans received orders to capture the Tulagi Island held by Japanese Forces. The 2nd Battalion landed on the morning of August 7 behind the 1st Marine Raider Battalion under Lieutenant Colonel Merritt A. Edson, and Rosecrans and his men subsequently repealed several Japanese attacks with the nightfall. In the evening of August 8, the Tulagi operation was declared successful, with 347 Japanese killed in action and another 3 surrendered. Marines from 2/5th Marines and 1st Raider Battalion lost 45 men. Rosecrans was subsequently decorated with the Silver Star for his leadership during the operation.