Nightingale still believed that the death rates were due to poor nutrition, lack of supplies and overworking of the soldiers. After she returned to Britain and began collecting evidence before the Royal Commission on the Health of the Army, she came to believe that most of the soldiers at the hospital were killed by poor living conditions. This experience influenced her later career, when she advocated sanitary living conditions as of great importance. Consequently, she reduced peacetime deaths in the army and turned attention to the sanitary design of hospitals.