Fourth-graders on a fossil hunt to mark the end of school ended up experiencing a horrific tragedy when one of their classmates was buried in a landslide.

One boy was killed and two others injured when soil loosened by recent heavy rains gave way on a path in Lilydale Regional Park near St. Paul. One child was treated and released at a local hospital while a second remained hospitalized in serious condition.

Rescue crews recovered the child’s body late in the morning Thursday after making sure the search could be safety resumed by emergency personnel.

The Park is a frequent destination of school groups because of fossils buried in bluffs along the Mississippi River. The city requires permits for fossil-hunting and requires people to waive their right to sue the city because of injuries or death.

The park department website says that “unsafe conditions” can exist in parts of the park.