Merando (plaintiff) lost his wife and daughter when their car was crushed by a tree as they drove through a national park. Merando’s wife and daughter were killed instantly. The tree had been topped and delimbed 10 years prior to the accident, causing the tree to die and its trunk to lean over the highway. Merando sued the National Park Service (NPS) (defendant) for negligence under the Federal Tort Claims Act (FTCA). The NPS moved the district court to dismiss Merando’s suit, arguing that the NPS was immune from suit under the discretionary-function exception to the FTCA. The district court granted the NPS’s motion. Merando appealed.