(AP) -- For the first time in 45 years, homicide has fallen off the list of the nation's top 15 causes of death, government health officials said Wednesday.
Murder dropped enough in 2010 that it was overtaken at No. 15 by a respiratory illness called pneumonitis that is seen mainly in people 75 and older.
This is the first time since 1965 that homicide failed to make the list, according to the Centers for Disease Control and Prevention.
The CDC's latest annual report on deaths contained several nuggets of good news:
-The infant mortality rate dropped to an all-time low of 6.14 deaths per 1,000 births in 2010. It was 6.39 the year before.
-U.S. life expectancy for a child born in 2010 was about 78 years and 8 months, up about a little more than one month from life expectancy for 2009.
-Heart disease and cancer remain the top killers, accounting for nearly half the nation's more than 2.4 million deaths in 2010. But the death rates from them continued to decline.
Deaths rates for five other leading causes of death also dropped in 2010, including stroke, chronic lower respiratory diseases, accidents, flu/pneumonia and blood infections.
But death rates increased for Alzheimer's disease, which is the nation's sixth-leading killer, for kidney disease (No. 8), chronic liver disease and cirrhosis (No. 12), Parkinson's disease (No. 14) and pneumonitis.
Homicide has historically ranked fairly low on the list. Its highest ranking in the past decade was 13th, in 2001, and that was due in part to the 9/11 attacks.
Murder rates have been decline in recent years in New York City, Detroit, Washington and other major cities. It was long thought that violent crime increased in a troubled economy, and that is what happened in the 1970s. But criminologists have had difficulty explaining the recent declines, and some have simply chalked it up to good police work.
Explore further: Colon cancer deaths down except in Mississippi
CDC report: http://www.cdc.gov/nchs/