Can low voltage cause injuries or even death?

Yes,
It depends mostly upon how much ampacity it has behind it.

Ask any welder....I think you'll find that an awfull amount of welding is done in the 10-20 volt range- with lots of amps!
Anything that can vaporise steel can hurt you.

The amount of current you receive is based on the resistance of your skin and tissue. Low voltage will not allow much current to flow under normal circumstances. Think about your car. Any circuit in there will provide plenty of current to kill you (100-200ma) but not enough voltage to push that much current through your body. People don't get electrocuted connecting up battery terminals in the rain.
If you are in a swimming pool immersed in water 12v might ring your bell but I still doubt it would kill you.
In the computer biz we had 3v power supplies at a couple hundred amps. There was danger but it was welding danger, not electrocution. I saw a guy light up a ring and it damn near burned his finger off. A cup of coffee mitigated the damage. I never put another piece of metal on my body.

Given the resistance of skin, it's unlikely to hurt you- V=IR and all, and it only takes current on the order of a tenth of an amp to kill, if it passed through your heart or head. Still not a good idea. OTOH, you can pass high-voltage, high-current tazer darts through your stomach, hand or thigh all day and feel nothing but pain because the current is siezing up muscles other than your heart.

There's an urban legend about a man who killed himself with a 9V battery by jamming the probes through the skin on his thumbs- would have put about 90ma through his heart, just enough to kill.
http://www.darwinawards.com/darwin/darwin1999-50.html

Normally, the body has an resistance of about 500kOhms or more (varying wildly), but the resistance goes down drastically if the skin is wet- electric chairs use probes dipped in saltwater to reduce the resistance to about 5kOhms. Hence why we put GFIC in kitchens and bathrooms but don't bother anywhere else- 120V is not normally enough to kill. 5mA is generally the threshold for danger.

[This message has been edited by SteveFehr (edited 03-24-2005).]