New Delhi, July 31 -- CEUTA, Spain - Prime Minister Pedro Sanchez flew to Ceuta on Thursday as Spain confirmed the death toll from the crossing had reached 18 and authorities said approximately 49,000 people had entered the North African enclave from Morocco in a single surge, the largest recorded crossing in the territory's history. The scale of the emergency, and the arrival of France as an active participant, turned what began as a Spanish border crisis into a European one before the day was out.

Sanchez arrived alongside Interior Minister Fernando Grande-Marlaska, a visit that transformed what had been an emergency managed by local and regional officials into a full national political event. Army soldiers were deployed along the Tara...