EAU CLAIRE, Wis. (AP) -- A hornet sting caused a fatal allergic reaction for a rural Eau Claire man.

Tom Ertz was on his porch when he was stung Saturday. His wife, Kathy Ertz, says her husband began having breathing problems, then dropped to his knees. She ran to get an allergy kit they kept on hand because Tom Ertz was allergic to shellfish. Then she called 911.

An Eau Claire County sheriff's deputy who was first to respond tried to resuscitate Ertz, but he was pronounced dead at Sacred Heart Hospital. He was 51.

The American Academy of Allergy, Asthma & Immunology says at least 40 deaths occur each year in the United States from reactions to insect stings.