New Delhi, July 17 -- AHVAZ - The blast hit close enough that hospital staff did not initially know whether the building itself had been struck. Children undergoing chemotherapy were moved from their beds. Patients on oxygen and ventilators were carried out of Shahid Baghaei Specialised Hospital as the sounds of airstrikes rolled through the city. By the time the night of July 15 ended in Ahvaz, a provincial capital in southwestern Iran's Khuzestan region, 211 pediatric cancer patients had been evacuated from one of the country's principal facilities for treating childhood tumors.

A staff member at the hospital described the detonation as "intense" and "so close" that the immediate assumption was that the structure itself had taken a dir...