Nothing in this chapter shall be construed to prevent any person maintaining any pipe or conduit in any public street, alley or public place by virtue of any law, ordinance or permit from making such excavation as may be necessary for the preservation of life or property when such necessity arises; provided, however, that the person making such excavation shall obtain a permit therefor within twenty-four hours thereafter, exclusive of intervening Saturdays, Sundays or legal holidays; and provided further, that all backfilling shall be done in accordance with this chapter. (Ord. 1970 NCS §3 (part), 1994; Ord. 1369 NCS §2 (part), 1979.)