sudden death of fishes in Fish only tank-urgent

[Santys]

hi all I have been running my 128 litre marine tank
successfully and all fishes were absolutely healthy
and fine.they were eating well and were all swimming about brightly
there were two tangs 1 inch and 1 clown 1 inch in the tank
water was looking crystal clear and fishes seemed to relish the new tank
2 days ago I just got to notice that one of the wires from the led adapter to the led strip was inside the water and the power was on and light was not on because one wire was inside the water.I got afraid that there might be a shock and immediately switched off the power and removed the led from the tank.the water had become a litte cloudy by then.

now two days later all the fish are dead.
only one of yhe clown is alive and he too is looking discoloured from the half of his body

what would have been the cause.does the wire pass on any current to the water and if so they would have all dided instantly right?

or has it deposited some poison in the tank
im completely baffled

can anyone please throw some light and let me know what to do now please

[Daniel62]

I would say that they were electrocuted:( Sorry

[snorvich]

I would say that they were electrocuted:( Sorry

My guess as well. (Note that tangs in this sized tank will not do well)

[Santys]

I took the water sample to kolathur to my friends ahop and tested it there
ammonia-0
nitrate-0
nitrite-0

so water parameters seem normal
one more thing happened a day back which I forgot to mention
the day before night I fixed a powerhead in the tank and the suction cup was loose.so I just closed the tank lid with the wire in between becos I did not want the powerhead to fall down in night into the substrate.
when I woke up next day tank was full of bubbles and hardly could see anything as water was gushing out of powerhead as it got unstuck from tank glass but did not fall into substarte.I removed powerhead and after an hour things were visible
could this be the reason?

[kw22]

Tangs in a 34 gallon are not going to do well anyways,a year max.

And probably electracution.

[humaguy]

I would think if the tank was zapped, the fish would have died immediately, and not 2 days later??

[fishhuman]

Even if they survived having 2 tangs in 34 gallons isn't good

[Scubaken]

If there was a current in the water that effected the equilibrium of the fish they would have been disorientated at worst, for a fish to have been electrocuted a "shock" would have to have been felt, this "shock" would have been caused by the current being grounded out, a human interaction for instance whilst the current was flowing through the water.
Shame all the same, do your homework before buying fish, small tank, big fish, always means trouble.
Sorry for your loss.