An 18-year-old hiker has been missing for almost a week after setting out to hike Haiku Stairs, one of Hawaii's most dangerous trails. Daylenn "Moke" Pua went missing the morning of February 27, when he was last seen boarding a bus in Waianae, Oahu. According to local news outlet KHON2, the teen -- who was visiting Oahu from the Big Island -- told family members that he planned to hike Haiku Stairs, also known as the "Stairway to Heaven." The stairs sit atop a perilous ridge, with steep cliffs on either side. According to the Honolulu Fire Department, Pua posted photos on social media indicating he was on the trail at around 11:00 a.m., the Honolulu Star-Advisor reports, but that was the last time he was heard from. The search effort has been extensive thus far, with the fire department, local volunteers, drone operators, and even the U.S.