How is power out one side of 220 only - Problem is with incoming 3-phase. But how?
In North America, most homes get 120/240 volt "split phase" - the local distribution transformer is single phase, and has a center-tapped secondary.  The center tap is grounded and becomes the Neutral.  There will be 240 volts between the two end terminals of the secondary, and 120 Volts from either end terminal and the center terminal.

It sounds like one of the two "hot" wires is broken.  Around here, such a fault would only affect the 8 - 10 (or so) homes fed from one transformer - but the number of customers affected would depend on the local distribution system.

(The high voltage distribution system here is 3-phase, and the step-down transformers are distributed between phases in an attemp to keep the phase loading balanced.)