The National Park Service (NPS) said Sunday that two people were found dead in Acadia National Park in Maine the day before, appearing to have fallen around 100 feet off an ice-covered cliff.

As CNN reports, the NPS said a couple, a 28-year-old man and a 30-year-old woman, were recovered by Park Service agents who were aided by the Mount Desert Island Search and Rescue as well as a helicopter from the Maine Forest Service. The Bar Harbor Police Department is investigating the issue alongside the NPS.

Their bodies were found Saturday morning by searchers on foot. The search also involved thermal imaging equipped to a Coast Guard helicopter, though it was unsuccessful in finding the hikers' bodies.

The hikers arrived in Bar Harbor, Maine, on Tuesday, CNN reports, and were last heard from Thursday afternoon. According to NPS, the female hiker had expressed interest in hiking Cadillac Mountain when speaking with family.

Concerns for the hikers first began around Friday afternoon when the couple did not check out of their hotel or return their vehicle. According to CNN, the search for the couple began Friday night when their family members reported they were late to check in.