The accident occurred on 17 August 2009 at 08:13 local time (00:13 GMT).
 There was a loud bang from turbine 2.
The turbine cover shot up and the 920-tonne (910-long-ton; 1,010-short-ton) rotor then shot out of its seat.
 After this, water spouted from the cavity of the turbine into the machinery hall.
 As a result, the machinery hall and rooms below its level were flooded.
 At the same time, an alarm was received at the power station's main control panel, and the power output fell to zero, resulting in a local blackout.
The steel gates to the water intake pipes of the turbines, weighing 150 tonnes (150 long tons; 170 short tons) each, were closed manually by opening the valves with hydraulic jacks keeping them up between 8:35  and 9:20 hours  (9.30 by official report).

The operation took 25 minutes, which is near the minimum time (highest speed) allowed for this operation.
 The emergency diesel generator was started at 11:32.
 At 11:50, the opening of 11 spillway gates of the dam was started and was finished at 13:07.

75 people were later found dead.

Nine out of the ten turbines were operating at the time, with a total output 4,400 MW.
Turbine 6 was undergoing scheduled maintenance, but was ready for a restart.

Oleg Myakishev, a survivor of the accident, described it as follows:
…I was standing upstairs when I heard some sort of growing noise, then I saw the corrugated turbine cover rise and stand on end.
Then I saw the rotor rising from underneath it.
It was spinning.
I could not believe my eyes.
It rose about three meters.
Rocks and pieces of metal went flying, we started to dodge them… At that point the corrugated cover was nearly at roof level, and the roof itself had been destroyed… I made a mental calculation: the water is rising, 380 cubic meters per second, so I took to my heels and ran for the turbine 10.
I thought that I wouldn't make it, I climbed higher, stopped, looked down, and saw everything getting destroyed, water coming in, people trying to swim… I thought: someone must urgently shut the gates to stop the water, manually… Manually, because there was no power, none of the protection systems had worked…
On 9 September 2009 at 17:40 local time (09:40 GMT), a fire started in the turbine hall during repair works.
 Around 200 people were evacuated.
There were no fatalities or injuries.
According to RusHydro the fire was extinguished "within a few minutes".
The accident occurred on 17 August 2009 at 08:13 local time (00:13 GMT).  There was a loud bang from turbine 2. The turbine cover shot up and the 920-tonne (910-long-ton; 1,010-short-ton) rotor then shot out of its seat.  After this, water spouted from the cavity of the turbine into the machinery hall.  As a result, the machinery hall and rooms below its level were flooded.  At the same time, an alarm was received at the power station's main control panel, and the power output fell to zero, resulting in a local blackout. The steel gates to the water intake pipes of the turbines, weighing 150 tonnes (150 long tons; 170 short tons) each, were closed manually by opening the valves with hydraulic jacks keeping them up between 8:35  and 9:20 hours  (9.30 by official report).
The operation took 25 minutes, which is near the minimum time (highest speed) allowed for this operation.  The emergency diesel generator was started at 11:32.  At 11:50, the opening of 11 spillway gates of the dam was started and was finished at 13:07.
75 people were later found dead.
Nine out of the ten turbines were operating at the time, with a total output 4,400 MW. Turbine 6 was undergoing scheduled maintenance, but was ready for a restart.
Oleg Myakishev, a survivor of the accident, described it as follows:
…I was standing upstairs when I heard some sort of growing noise, then I saw the corrugated turbine cover rise and stand on end. Then I saw the rotor rising from underneath it. It was spinning. I could not believe my eyes. It rose about three meters. Rocks and pieces of metal went flying, we started to dodge them… At that point the corrugated cover was nearly at roof level, and the roof itself had been destroyed… I made a mental calculation: the water is rising, 380 cubic meters per second, so I took to my heels and ran for the turbine 10. I thought that I wouldn't make it, I climbed higher, stopped, looked down, and saw everything getting destroyed, water coming in, people trying to swim… I thought: someone must urgently shut the gates to stop the water, manually… Manually, because there was no power, none of the protection systems had worked…
On 9 September 2009 at 17:40 local time (09:40 GMT), a fire started in the turbine hall during repair works.  Around 200 people were evacuated. There were no fatalities or injuries. According to RusHydro the fire was extinguished "within a few minutes".
2009 Sayano-Shushenskaya power station accident