Lineman dies of electrocution - power cables of two different areas on same electric pole-supply from one area not off

An electric pole had power cables from two different areas. One is de-enerzized, another one not, as the information of existence of power cables from two different areas on same pole is not known to the lineman. 

Power was switched off from the area in which lineman is working. 

Assuming no power, lineman climbed up the pole and was electrocuted by contact with energized cables from other area on the same pole.

If such conditions exist i.e. presence of cables from different areas on the same pole, then display of such information as line diagram on the pole itself can help workmen to know the details and take necessary action.