Transcript for Body found in search of missing woman in Costa Rica: Authorities

this Monday evening to the disappearance of an American woman on the last day of her I have case in Costa Rica. A witness says he was seen leaving with her bags the day she was supposed to go home. And now investigators with a disturbing find. Here's ABC's Eva pilgrim. Reporter: Tonight, authorities in Costa Rica say they have found a body during their search for an American woman who vanished on vacation. Second day, the hot springs. Costa Rica! I can't believe it! Reporter: Carla stfaniak was celebrating her 36th birthday with her sister-in-law. How they welcome me for my birthday! Reporter: Staying an extra day on her own at this airbnb. Her family says she texted last Tuesday night, "It's raining hard, power went off. Super sketchy." Before her phone died, she said she was too tired to go out. The owner of the airbnb told the family she left with her bags the next morning at 5:00 A.M. Her flight wasn't until 1:30. She's only 20 to 30 minutes from the airport. So, this story doesn't make sense. Reporter: A woman's body found near the airbnb. Tonight, authorities say they will test what appears to be blood found inside the home. David, authorities will now work to identify the body. They have not yet named any suspects.

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