Gohna Lake dam-burst
The Gohna Lake dam-burst was a flood in Garhwal Region of India in 1894 caused by a landslide induced temporary lake.
There are different versions of different sources on the extent of damages to life but they are very sure about the damages to the regions.
First account is that "On 6 September 1893, a tributary of the Alaknanda River called Birahi Ganga was blocked by ~5000 million tonnes of rock mass that rolled from a 900 m high valley flank. The debris blocked the river forming a lake 270 m high, 3 km wide at the base and 600m which was constructed much above the anticipated flood level. Similarly, eight suspension bridges between Chamoli and Haridwar were dismantled in order to protect them from being washed away by the anticipated flood. As predicted, on 25 August 1894, water began to trickle over the dam and at midnight the dam was partially collapsed, sending flood surges downstream. The flood lasted until the morning of 26 August causing unprecedented damage to the property around Srinagar, Uttarakhand town; however, no loss of life was reported." 
Whereas according to another version "The tale began in September 1893, with a massive landslip at Gohna, Garhwal District, in the north of India, which created a natural dam across the River Ganges at Birahi, above the Alaknanda valley. The district surveyor T. H. Holland, alongside an army engineer, made a detailed report of the situation, suggesting that the accumulation of water would eventually force the dam, flooding the entire Alaknanda valley. A soldier, Lieutenant Crookshank, was positioned to keep watch on the lake, with a telegraph cable that would allow him to sound an alarm. Here, Crookshank collected data that enabled army engineers to accurately predict when the dam would overflow. The engineers were only 1 day short, and the dam broke on 25 August 1894, propelling a deluge of 10,000 million cubic feet of water into the valley. Fortunately, in the few days before the burst, authorities had been able to evacuate the valley and although the old part of the city of Srinagar was lost, there was only 1 death caused by the flood."