Lisanne Froon & Kris Kremers

On April 1, 2014, Kris Kremers (21) and Lisanne Froon (22), two Dutch women volunteering in Boquete, Panama, set out for a day hike on the popular Pianista trail near the continental divide. Photos from Lisanne's camera show them reaching the summit of the trail around 1:00 p.m. and then continuing beyond the marked path into more remote terrain. They were never seen alive again.

Phone records show that at 4:39 p.m. that day, Kris's phone made an emergency call to 112 (the European emergency number) and then to 911 (the Panamanian number). Lisanne's phone made a similar call shortly after. None of the calls connected—the area had extremely limited cell coverage. Over the following days, more emergency calls were attempted from both phones, but none went through. The phones' batteries were gradually depleted, with Kris's phone dying on April 5 and Lisanne's being periodically turned on until April 11.

Ten weeks later, Lisanne's backpack was found on a riverbank by a local woman. Inside were the phones, Lisanne's camera, cash, and their passports—none of which had been taken. The camera contained 90 photos taken in darkness between 1:00 and 4:00 a.m. on April 8, showing jungle vegetation, rocks, and what appeared to be scraps of material. Some interpreted these as distress signals; others as attempts to use the flash as a light source.

Skeletal remains of both women were found over subsequent months along the same river system. Some bones showed signs of bleaching inconsistent with the timeline, and a foot was found inside a boot still laced up, raising questions. The official Panamanian conclusion was that the women became lost and died of exposure, starvation, or a fall. Dutch investigators were unable to rule out foul play. The case has generated intense online debate about whether their deaths were accidental or criminal.