What is the lowest voltage recorded that has caused fatalities?

The best answer I can find is 60 volts. I'm not sure if this is AC or DC. However, it's not just the voltage that kills. You can be electrocuted by a car battery if you make a good connection to both poles. Most car batteries have around a 600 amp output. Even at 12 volts, this can be deadly. Keep in mind also that it's easier to be killed by DC than by AC. ---- IF YOU'RE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS. If you do this work yourself, always turn off the power at the breaker box/fuse panel BEFORE you attempt to do any work AND always use a meter or voltage indicator to insure the circuit is, in fact, de-energized.