At around 08:30 on October 13, 2026, an electrical transformer exploded in the tunnel at Ihlamurkuyu station on the M5 Üsküdar-Sultanbeyli metro line in Ümraniye, causing a fire that was reported around 08:45.
The explosion and fire disrupted metro services during the morning rush hour, leading to heavy crowds at metro and bus stations as commuters sought alternative transportation. Firefighters, medical teams, and police were dispatched to the scene.
One passenger affected by smoke was treated in an ambulance. A witness said the metro train hit hanging cables, causing the explosion and fire.
Another witness, Gökhan Fırat, said: "Kabloda patlayınca yangın olmuş, yaralı var mı bilmiyoruz".
Metro İstanbul announced that services were partially suspended, operating only between Üsküdar-Çakmak and İmam Hatip Lisesi-Sultanbeyli stations due to a technical failure/malfunction.
Passenger Hafize Zeynep described the experience: "Biz trendeydik. Birden patlama sesi oldu. Ne olduğunu anlayamadık. Duman çıktığını gördük. İstasyondakiler sıkıştı. Biz de acil butonuna bastık ama kapılar açılmadı. Biz de mandalı kendimiz aşağı çekerek çıktık. Sonra itfaiye geldi. Hiçbir şekilde bizi çıkarmaya gelen olmadı. Biz kendimiz çıktık. Seferler durdu. Belki bugün açılmayabilir". Another witness, Gökhan Fırat, said: "Kabloda patlayınca yangın olmuş, yaralı var mı bilmiyoruz".
An investigation into the cause of the fire has been launched.