A sister whose 3-year-old brother died 50 years ago of poisoning -- the leading cause of unintentional U.S. injuries -- said everyone needs to be vigilant. Cathy Seifried of Texas said her brother drank a bottle of rat poison and although every attempt was made to save his life, the hospital was 30 miles away and he died. She said her family never recovered. The American Association of Poison Control Centers is joining local poison centers and poison prevention partners nationwide in marking the 50th anniversary of National Poison Prevention Week. \"If our family would\'ve had access to the education, outreach and treatment services that today\'s poison centers offer, we may have avoided the heartbreak and devastation caused by my brother\'s death,\" Seifried said in a statement. Poison centers respond to calls 24 hours a day, seven days a week in order to help those who have been exposed to toxic substances. Dr. Rick Dart, president of the American Association of Poison Control Centers, said poisoning is the leading cause of death from unintentional U.S. injuries in the U.S. -- ahead of motor vehicle crashes and guns. In 2010, U.S. poison centers answered more than 3.9 million calls, including nearly 2.4 million calls about human exposures to poisons. About 75 percent of all calls to poison centers originated in people\'s homes, and about 71 percent of the people who called with poison emergencies were treated at home following the advice of poison center experts, saving millions of dollars in medical expenses, Hart said. \"If the unthinkable happens, it\'s good to know help is just a phone call away,\" Dart said. \"Program your cellphone with the Poison Help number and post it near your home phone: 1-800-222-1222.\"