blasts and wound allocation

I am reffing a game right now between... well it doesn't matter who. The question is, the rule for blasts say that you work out the unsaved wounds and work it out as a normal shooting attack. Does this mean what is under the blast marker? that would make most sense to me, however it doesn't say. So, if you work out wounds and saves, then any UNSAVED wounds are worked out like a normal shooting attack then peeps that weren't even under the blast take a wound???? what if a person was under there that had a 2+ armor? he takes a wound in a group that needs a 4+? please someone clarify if they can. Thank you

As the rule states, you work out wounds normally. The blast just determines how many are hit. It is still the models closest to the firing unit that are hit first (even if they were not under the blast template.

Barrage weapons target those under the blast but normal blast weapons do not and wounds are allocated to the closest model as normal.

Does it mean that if I hit several models from 2 different units, all the wounds will go only to the target unit? Even if there were a lonely almost dead soldier?

Nope, hits are allocated to units, not models. So if you hit one model from unit A and three models of unit B, you allocate one hit to unit A and three hits to unit B.