A backpacker who was hiking in a “remote” location in a Michigan national park has died as a result of a “sudden onset” medical emergency, authorities said.

The 37-year-old woman was hiking with her partner near Lake LeSage in Isle Royale National Park on Monday, August 12, when she “suddenly experienced medical complications,” according to a National Park Service press release.

Her condition “worsened,” the NPS added, and she quickly “became unable to walk, lost consciousness and stopped breathing.” Passersby attempted to give the hiker CPR, but their attempts were unsuccessful and she died.

According to the NPS, other backpackers who were in the same area as the couple contacted Michigan State Police via a “delayed 911 text message,” and park rangers and emergency medical technicians were dispatched to the group.

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Due to the remote location, rangers and paramedics stayed with the group overnight. On the morning of August 13, Isle Royale National Park staff escorted the group off the island.

A park ranger told NBC News that the small crew stayed with them overnight because a larger crew was needed to transport the woman’s body back to the mainland.

PEOPLE could not immediately reach Isle Royale National Park staff for comment.

Located in a remote area of ​​northern Lake Superior, Isle Royale preserves and protects “the natural, cultural and wild resources of a freshwater archipelago in Lake Superior,” according to the NPS.

The investigation into the woman’s death is ongoing, the Park Service added. The cause of death has not yet been released.

“The Isle Royale community wishes to extend its sincere condolences to the family and friends of the deceased,” the NPS added.