(CNN)Initially, Ricardo Ramos thought it was a drill when the ground began to shake on Tuesday. This was the day for it, after all.
Hours after an earthquake drill in Mexico City, the real thing struck
Each year on September 19, cities across Mexico stage emergency disaster simulations and evacuations that bring people out in droves. The drill falls on the anniversary of an 8.0-magnitude earthquake that shook Mexico's capital in 1985, burying nearly 10,000 people amid its rubble.
The annual drill began in Mexico City around 11 a.m. on Tuesday, just like it does every year. The alert went out over radio, television, phones and public loud speakers. People left homes, offices and shops and headed to designated safe areas promoted days ahead of time.
Then, around two hours later, the real thing struck. Ramos quickly realized this was not a drill.
The irony of the situation was apparent to Mexicans, for whom the drills are a way of life, even a minor annoyance. Many noted the contrast between the orderly, almost mundane quality of some drills and the chaos of real life.
In a first-person account posted to CNN partner Univision Network's website, reporter Janet Cacelin wrote about her experience in the network's office building. "We headed out to Paseo de la Reforma Avenue and once again saw the same office workers who hours earlier were chatting, playing and getting bored during the drill. Many had said it was a waste of time," she said.
The 1985 disaster led to changes in building codes and enhanced emergency preparation measures, including the annual drills. This year was slightly different. The country was on edge from a September 7 earthquake that struck off the southern coast, triggering tsunamis and sending shockwaves as far as Mexico City and Guatemala City. Five states suspended drills in solidarity with those affected, and to avoid alarming residents.
Elsewhere across the country on Tuesday, the drills continued as usual. In Puebla, the local Red Cross touted the success of the city's drill on social media, sharing pictures and saying the exercise helps prepare people for natural disasters, including earthquakes.
"Our volunteers will always be here to help you," the agency said.
Dorothy Munoz knew what to do. She was watching a television special in her Mexico City apartment marking the 1985 catastrophe as the ground began to shake. A fish tank fell to the floor along with decorations and furniture. She grabbed her dogs and headed for the streets where people had gathered. Officials told them to wait to return to their apartments until buildings were checked for structural damage.
Others, however, were struck by how different it was from the drill. Cacelin noted there was no 30-second warning before the temblor to give them time to gather their composure and listen for instructions. Instead of hiding under desks, Cacelin said people ran for the doors, including her.
When she made it outside, instead of laughing and joking, people were crying and desperately searching for loved ones.
"This time there was no alert, we only felt the temblor," she wrote. "The earthquake took us by surprise."