A tiger shark recently killed a U.S. tourist off Costa Rica’s Cocos Island in the Pacific Ocean, the first-ever recorded incident for the national park.

According to news reports, the diver was a 49-year-old woman who was attacked by a female tiger shark, which also injured her male Costa Rican dive guide. The divers were surfacing when the attack took place.

Cocos Island lies about 500 kilometers/300 miles off the Costa Rican coast, and is known to be a habitat for many shark species.

The Costa Rican Environment Ministry emphasized last week’s encounter was an “isolated incident.”