美国有线新闻 CNN 墨西哥7.1级地震 与32年前同一天发生地震（在线收听）

Another natural disaster has struck the North American nation of Mexico. A little over a week after a magnitude 8.1 earthquake occurred near the country's southern coast, a magnitude 7.1 tremor hit yesterday. This one in central Mexico and it caused some buildings to collapse in the capital of Mexico City, about 75 miles away.

Initial reports indicated that dozens of people were killed nationwide, but we don't know yet how many. Information was pouring in as we produced this show.

Schools were closed in the Mexican capital. The airport was closed. Mexican President Enrique Pena Nieto ordered the evacuation of damaged hospitals with patients being moved to other medical facilities.

This earthquake came exactly 32 years to the day after another tremor killed about 9,500 people in and around Mexico City.

ALLISON CHINCHAR, CNN METEOROLOGIST: The depth was about 32 miles. That may not seem that deep to you, but that plays a very important role in terms of the vicinity. So, again, here is where it's located, just for some reference point, not quite, a little bit further to the north and west from where that 8.1 earthquake happened about a week ago.

Here is a look at the population, about 28 million people felt sometime of weak shaking, 20 million felt some type of moderate shaking and you have about 9 million people that experience some type of strong shaking. We talked about the depth, OK? Thirty-two miles, which is about 51 kilometers, OK? Up to 70 kilometers, it's still considered a shallow earthquake.

So, even though that may not seem like it would be at 32 miles, it is and this grand scheme of earthquakes, that is still considered a shallow earthquake. That's important because shallow earthquakes often cause the most damage, compared to the ones that are deeper, regardless of the strength. But this also was a relatively strong earthquake.

When we talk about fatalities, it's estimated to be in this orange range, where it could be anywhere from 100 up to 1,000. All of this information, by the way, coming from the U.S. Geological Survey, in terms of economic losses as well.

Now, frequency. We often get about 15 earthquakes that are between seven and 7.9 every year. So it's not uncommon to get this.