Going with the lateral thinking tag,

The father should tell the son to duck(then pull the lever) and since the child is young, he may be small enough to fit under the train. An article on what to do when stuck on a subway rail, "A final option is to simply lie flat — there may be enough clearance for the train to pass over you".

So

This would save both the people on the train and the son.

Going with the lateral thinking tag,

The father should tell the son to duck(then pull the lever) and since the child is young, he may be small enough to fit under the train. An article on what to do when stuck on a subway rail, "A final option is to simply lie flat — there may be enough clearance for the train to pass over you".

So

This would save both the people on the train and the son.

Here is the video where it was found at time 0 - 23 seconds.

Going with the lateral thinking tag,

The father should tell the son to duck(then pull the lever) and since the child is young, he may be small enough to fit. An article on what to do when stuck on a subway rail, "A final option is to simply lie flat — there may be enough clearance for the train to pass over you".

So

This would save both the people on the train and the son.

Going with the lateral thinking tag,

The father should tell the son to duck(then pull the lever) and since the child is young, he may be small enough to fit under the train. An article on what to do when stuck on a subway rail, "A final option is to simply lie flat — there may be enough clearance for the train to pass over you".

So

This would save both the people on the train and the son.