URBANA, Iowa (AP) — A woman has died after being attacked by a cow on her farm near Urbana.

The Benton County sheriff's office told KCRG-TV that 60-year-old Jean Fee was feeding the cows Saturday afternoon when one of them attacked her. She died at a Cedar Rapids hospital.

Fee was with her 23-month-old grandson when the attack happened, but authorities say he wasn't hurt.

The sheriff's office says family members haven't had trouble with the cows before.

None of the news reports indicated what type of cow it was that attacked her.

An article in the Des Moines Register said there were three calves in the pasture when the attack occurred.

“It’s pretty unusual for a cow to become aggressive,” Terry Engelken, an associate professor at Iowa State University’s College of Veterinary Medicine, said in the Register article. “We have a few instances of (cow attacks) across the country every year, but it’s uncommon. For it to result in a fatality is very uncommon.”

 Copyright 2011 The Associated Press.