PARIS — Fathi Bayoudh was a respected officer and doctor in the Tunisian military, but on Tuesday night at Istanbul’s main airport he was a father worried about his wayward son.

Dr. Bayoudh, 58, had arrived in Istanbul weeks earlier to find his son, Anouar, 26, who had run off to join the Islamic State group in Syria. When he got word through the Tunisian Embassy in Turkey that the Turkish authorities had detained Anouar in a town near the border with Syria, he called his wife in Tunisia. They arranged to meet at Ataturk airport before heading to the town where Anouar was being held.

The two doctors were hoping to take their only son home.

But shortly before 10 p.m. on Tuesday, as he waited at the airport for his wife to arrive, three suicide attackers opened fire and then blew themselves up, killing at least 41 people, including Dr. Bayoudh. His death was confirmed Wednesday by Tunisia’s Ministry of Foreign Affairs. His wife was not hurt in the attack.