Lebanese President Michel Aoun says the probe into a devastating blast in Beirut is “very complex” and won’t be finished quickly. Responding to calls that he step down, Aoun told French TV station BFMTV in his first interview with foreign media since the Aug. 4 blast that it would be “impossible” because it would create a power vacuum. The cause of the fire that ignited nearly 3,000 tons of ammonium nitrate stored at Beirut’s port remains unclear.