A blind Detroit woman has gone missing during a trip to Peru, sparking an international investigation, The Detroit News reports. Authorities are investigating the disappearance of Carla Valpeoz, 35, an avid traveler who is legally blind. “Time is ticking,” her brother, Carlos Valpeoz, told The Detroit News, noting that his sister was supposed to arrive in the United States on Saturday but failed to show up for her return flight. “This has been escalated to an extremely serious situation at this point since it’s been so long since she was last seen.” He said she went to the South American country for a wedding but then went off on her own last Tuesday. Peru authorities say a passport check confirmed that Valpeoz subsequently visited the historic Machu Picchu citadel in the Andes Mountains. Photos posted online showed her reaching a pinnacle and hanging out with a new group of friends, dining in another town and visiting hot springs, according to the report. The group returned to the hostel with Valpeoz and she went to bed first, her brother was reportedly told, but both she and her belongings were gone when her roommate woke up the next morning.