Who saved lives of Athenians when attacked by Xerxes' army?

Answer 1

Some nearby cities took in the Athenian families when the men of military age abandoned the city and embarked on the warships to help overcome the Persian fleet.

According to Herodotus, the Delphic oracle was consulted when the Persian Army approached, and it said that Athens would be protected by wooden walls. Some built wooden walls to defend the Acropolis and perished, but Themistocles convinced them that the wooden walls were the triremes of the Athenian fleet. The city was evacuated and destroyed by the Persians, but Themistocles and his 'wooden walls' were part of the allied fleet which demolished the Persian Navy at the Battle of Salamis, the turning point of the war. If the Athenians had remained to defend the city they would have been overwhelmed, killed and enslaved. It could be said that Themistocles saved their lives by organising the oracle to convince the Athenians to evacuate the city.

We must of course recognise that Delphi had a remarkable spy system to keep track of events in the Greek world, to anticipate and generate oracles appropriate to the questions being sent to their Oracle. No doubt Themistocles helped compose the answer and provided an appropriate bribe to facilitate this support to the strategy which he was trying to push to the Athenian people as the Persians progressed their ponderous advance towards Greece.

The strategy which he was working to is explained in the answer in WikiAnswer What_was_the_battle_at_Thermopylae_involving_the_300_and_who_won