The CCTV footage shows several people in the pool at an apartment complex in Florida when one girl's body suddenly freezes after she touches the metal hand rail.

Her father, sitting on the steps just feet away, realises something is wrong and quickly pulls his daughter to safety, getting shocked in the process.

As others flee the pool amid panic, a second girl is seen still paralysed with her hand stuck to the railing.

The girl's grandfather then runs in and pulls her out. The footage shows him falling back onto the pool deck as the electric current runs through his body.

A 10-year-old boy was also shocked, US media reprted.

All three children survived and were sent home after spending four nights in hospital.

Investigators have blamed the incident in April on an unconnected ground wires in the pool's pump house, WFOR reported.