At 9:04:35 am, the out of control fire aboard
Mont-Blanc finally caused her highly volatile cargo to explode. The ship was instantly disintegrated; the remains of her hull launched high into the air. The blast travelled at more than 1,000 metres per second. Temperatures of 5,000°C and pressures of thousands of atmospheres accompanied the moment of detonation at the centre of the explosion.
[40] White-hot shards of iron rained down upon Halifax and Dartmouth.
[41] The barrel of one of
Mont-Blanc's guns landed approximately 5.6 kilometres (3.5 mi) north of the explosion site near
Albro Lake in Dartmouth, while part of her anchor landed 3.2 kilometres (2.0 mi) south at
Armdale.
[42]
A resulting cloud of white smoke rose to over 3,600 metres (11,800 ft).
[43] The shock wave from the blast travelled through the earth at nearly 23 times the
speed of sound and was felt as far away as
Cape Breton and
Prince Edward Island.
[44] An area over 160 hectares (400 acres) was completely destroyed by the explosion,
[42] while the harbour floor was momentarily exposed by the volume of water that vaporized. A
tsunami was formed by water surging in to fill the void,
[45] which rose up as high as 18 metres (60 ft) above the harbour's high-water mark on the Halifax side.
[46] Imo was carried onto the shore at Dartmouth by the tsunami.
[47]
Over 1,600 people were killed instantly while 9,000 were injured.
[48] Every building within a 26 kilometres (16 mi) radius, over 12,000 total, was destroyed or badly damaged.
[45