The first occurred on Saturday in Lefaga where a one-year-old boy is believed to have drowned behind the family home.
The police said the child was left unsupervised.
The second death was that of a four-year-old girl in Ti'avea, who died on Sunday after being hit by a mini-van while she was crossing the road.
The police said the driver has been charged with negligent driving causing death.
Then on Monday, a three-year-old was killed while watching television with her siblings when the television fell on her head.
