The U.S. death rate rose last year, and 2017 will likely be the third straight year of decline in American life expectancy, according to preliminary data. Death rates rose for Alzheimer’s disease, diabetes, flu and pneumonia, and three other leading causes of death, according to numbers posted online Wednesday by the Centers for Disease Control and Prevention. Full-year data is not yet available for drug overdoses, suicides or firearms deaths. But partial-year statistics in those categories showed continuing increases. For decades, life expectancy increased, rising a few months nearly every year. But 2016 was the second year in a row in U.S. life expectancy fell, a rare event that had occurred only twice before in the last century. The overall death rate rose a little less than one percent, to about 734 deaths per 100,000 people. The rate dipped slightly in 2016 despite a record number of deaths that year, so its rise in 2017 is more reason to expect life expectancy will worsen.