PIERRE, S.D.(WNAX)- The rolling power blackouts during the extensive February cold wave are still being investigated.

South Dakota Public Utilities Commission Chairman Chris Nelson says the Southwest Power Pool is leading the study.

Frigid air plunged deep into Texas, causing damage to power plants, forcing utilities in fourteen states to roll the outages to prevent the entire grid from collapsing.

Nelson says the power operators need to come up with a plan to avoid similar issues in extreme weather.

Nelson says they hope to hear some details before winter sets in again.