The blaze was at the Rivers Edge apartment complex at the corner of N.C. 210 and Pine Knoll Drive.
Spring Lake police said the fire broke out about 3:45 p.m. They reported that four of the 12 units were occupied, but officials did not know how many people were displaced.
Clark said firefighters had determined that the lightning struck one end of the roof, and flames then spread through the common area that connects above the six top-floor units.
The top-floor units were destroyed, Clark said.