Nel labirinto question

The ending was pretty ambiguous and doesn't give you a definite answer about what happened to Magda, but here's what I think: Katja accidentally killed her by trapping her inside the bunker. We know for a fact that Magda spends a lot of time playing alone in the woods surrounding her house, so when Katja started talking about the bunker next to the labyrinth, my brain immediately made the connection. Just like Katja and other lost girls before her, it's entirely possible that Magda found the bunker and was spending her time there. Furthermore, when Katja goes to seal the bunker forever, she brings attention to the fact that it's May 3rd 9.30 pm, the exact moment we know Magda disappeared. This leads me to believe that she died in the bunker after Katja unknowingly sealed her inside, which means that she was right next to her house the entire time. It's actually pretty horrifying if you stop to think about it. What do you guys think?