Station was activated along with 1st alarm assignment @ 16:30 for a rekindle structure fire.  Crews were still cleaning equipment so the squad (with 4) and Engine 2 (with 2) responded immediately, holding all other units in station.  Crews arrived to find smoldering spot on side C.  Crews headed to the attic and extinguished hot spot.  Crews investigated more and found nothing.  Crews returned in service a hour later.