Explosion from Power Transformer

A woman hurt

Terrible. What does a transformer do? It changes voltage and current. To send electricity across long distance, you need high voltage and low current to lower resistivity. After electricity is generated, the transformer changes it to high voltage for lower current. Current is the flow of electrons through the wire, which you can imagine would dissipate much more power than high voltage. (All power transmission through the wire must, by the law of resistance, dissipate power.) However, high voltage is dangerous, so transformers are placed to downgrade the voltage and upgrade the current as you get closer to the city. Power is dissipated faster, but as long as the wire is short distance to the destination, the loss of efficiency isn't much in return for increased safety.

The voltage that reaches the house and apartment is a mere 120 volts (which won't cook you as much as a higher voltage would), the standard in the United States. International standard is, of course, different.