Concerns are rising over land subsidence occurring above Athens Metro Line 4, specifically in the Kypseli neighborhood. Reports are surfacing regarding issues with the ground settling as construction progresses on the extension of the metro line. Investigations are underway to determine the exact cause and extent of the problem. Authorities are working to assess the potential impact on nearby buildings and infrastructure in Kypseli. The timeline of these events and the factors contributing to the subsidence are currently being investigated. Details about when the problems initially began and the current understanding of the situation are being sought to ensure public safety and mitigate further damage.