In Acapulco, 59-year-old Enedina Ramirez Perez was having breakfast, enjoying the holiday with about 20 family members, when her hotel started to shake.
"People were turning over chairs in their desperation to get out, grabbing children, trampling people," the Mexico City woman said. "The hotel security was excellent and starting calming people down. They got everyone to leave quietly."
The quake struck 170 miles (273 kilometers) southwest of Mexico City, where people fled high rises and took to the streets, many in still in their bathrobes and pajamas on their day off.
"I started to hear the walls creak and I said, 'Let's go,'" said Rodolfo Duarte, 32, who fled his third-floor apartment.
"This is really strong," said Gabriel Alejandro Hernandez Chavez, 45, an apartment building guard in Mexico City. "And I'm accustomed to earthquakes."
The USGS initially calculated the quake's magnitude at 7.5, but later downgraded it to 7.2. It said the quake was centered 22 miles (36 kilometers) northwest of the town of Tecpan de Galeana, and was 15 miles (24 kilometers) deep.
In many cases of earthquakes in Mexico, it can take time to receive word from remote areas near the epicenter, where damage could be more extensive. No one answered the phone at the city hall for Tecpan de Galeana.
Mexico City itself is vulnerable even to distant earthquakes because much of it sits atop the muddy sediments of drained lake beds that quiver as quake waves hit.
The magnitude-8.1 quake in 1985 that killed at least 6,000 people and destroyed many buildings in Mexico City was centered 250 miles (400 kilometers) away on the Pacific Coast.