Narrated from Abu Jaffar Ibn Muhammad Ibn Ali (ra).
Three or seven days, AFTER YOU SEE A FIRE FROM THE EAST, EXPECT TO SEE THE APPEARANCE OF AL-I MUHAMMAD [HAZRAT MAHDI (AS)], an angel from the sky will call out the name of Hazrat Mahdi (as), and everyone in East and West will hear that voice. So much so that those asleep will wake from fear, those standing will squat down, and those seated will rise to their feet.
(Al-Burhan fi Alamat al-Mahdi Akhir al-zaman, p. 32)
It is revealed in the hadith that “people may begin to expect the appearance of Hazrat Mahdi (as) when a fire is seen from the East.” On 15 November, 1979, the world’s fourth largest tanker, the 150,000 ton Romanian Independenta carrying 95,530 tons of crude oil struck a Greek steamer as it approached Istanbul, the final center of the Islamic world, causing a fire that blazed for several days in the sea in front of Haydarpaşa.
According to the information provided in the hadith, this is an event that took place during the days when Hazrat Mahdi (as) set foot in Istanbul. Through this event, the coming to Istanbul of Hazrat Mahdi (as) was announced in such a way that everyone in the world could hear, both the human world and the world of the djinn. People were thus told by Allah that Hazrat Mahdi (as) had come to Istanbul, both by a noise as loud as thunder, a giant flame that blazed for several days, by light and smoke, and by further explosions that took place from time to time.
* Pictures are taken from http://www.sihirlitur.com/olaylar/tanker/galeri1.html#