Two of the suicide bombers who carried out attacks in Brussels on Tuesday are brothers. Khalid and Brahim el-Bakraoui, both Belgian nationals, had criminal records, according to Belgian officials Wednesday. At least 31 people were killed and 270 injured in the attacks at the city’s main airport and at a subway station in central Brussels. A manhunt is underway for a suspect who was recorded by a security camera alongside Ibrahim el-Bakraoui at the airport. Tuesday's violence was the deadliest terror attack in Europe since the Paris attacks in November.