The eruption began on February 20, 1943, at about 4:00 PM local time. The center of the activity was a cornfield owned by Dionisio Pulido, near the town of Parícutin. During that day, he and his family had been working their land, clearing it to prepare for spring planting. Suddenly the ground nearby swelled upward and formed a fissure between 2 and 2.5 meters across. They reported that they heard hissing sounds, and smoke which smelled like rotten eggs, indicating the presence of hydrogen sulfide. Within hours, the fissure would develop into a small crater.