Raleigh Police Department spokesman Jim Sughrue says three people were swimming at the Dominion Creek Apartments complex pool.
One of the friends could not swim. That person slipped in to the deep end, and was unnoticed for a while.
Friends pulled the victim, 23-year-old Demtris Jay Adams of Raleigh, out of the pool and began CPR.
He was transported to Wake Med and is in critical condition.
Two of Adams' friends were cited for second degree trespassing.