After the suspicious deaths of three French soldiers, General Charles de Lorencez became concerned about the fate of the sick in Orizaba.

On the pretext that a letter from Mexican General Ignacio Zaragoza threatened their well-being, he sent his army (about 7,000 men) to help them.

They were caught near Fortín and decided to wheel about and face the French, but suffered five killed and twelve captured, with the rest fleeing for their lives.

Upon hearing the news of the engagement, General Ignacio Zaragoza, who was near Orizaba, set off for Puebla in the evening.

He made a proclamation there justifying his conduct by the "vile attack" with which Zaragoza would have threatened French patients had he not fled.