Ahsan Manzil without the dome?

Ahsan Manzil — the residence of the Nawab family — was completed in 1872 but who knew at that time that a dome would later adorn the palace? The twist of fate came with a devastating tornado, in 1888, which destroyed much of the structure. Restoration was called for and that was when the dome was added. 

To paint a picture of what this majestic building looked like just after the catastrophe, a line from an eyewitness account may be apt here. In his memoir, The Reminiscences of Dacca, Hriday Nath Majumdar wrote, "We advanced then towards the

'Assan Munzil' which we saw bereft of its grand roof and all furniture lying scattered over the spacious lawn." 

By the way, the tornado was not the only time disaster struck the building: it was damaged again in the earthquake of 1897, but that's a story for another day!

Sources-Dhaka: Smriti Bismritir Nagari (Volume-1) by Muntassir Mamoon; The Reminiscences of Dacca by Hriday Nath Majumdar; Banglapedia