It was a safe airport. I have been regularly flying in/out to either IST or SAW as SLF for over 10 years, 4-20 times per year. Everyone gets a security check as you enter the airport, before getting to the check-in desk. After Check-in and immigration (Turks record people in and out) you get another security check before access to the lounge/duty free shops etc. On occasions, you get a third check as you enter the departure gate area. On Saturday 25 June, I was returning to the UK with an unusual electronic device. It was picked up and given extra security checks by both security points in use that day.
While facts are sparse at the moment, I don't think you can stop suicide people, they could have easily been attacking a bus or train station, with similar results. Bit strange they done it during Ramadan, when I understand Muslims are meant to refrain from fighting (as well as no food/drink in daylight hours etc). My thoughts and prayers to the relatives of the people killed/injured.