After the Maghrib (sundown) call to prayer, spectators began to flood the one-hectare open yard inside the Lirboyo Pesantren (Islamic boarding school) complex in Kediri, East Java. That day, the third Saturday of April, roads leading to the school were packed. Street vendors and vehicles crowded roadsides, spilling over into street lanes.

Trucks and pickups were lined in a 500-meter radius on streetsides. These are the vehicles that had brought