Transcript for A massive earthquake struck Mexico on Friday

that warm weather. Sam, thanks so much. Overseas, the deadly aftermath of that earthquake in Mexico, striking fear but causing little damage until a military helicopter surveying the area spun out of control, crashing to Earth on top of a bus. Here's ABC's Marcus Moore with the freak accident. Reporter: Tonight, the horrifying tragedy in the middle of a major earthquake. The Mexican military helicopter, carrying high-ranking government officials, slamming into vans, killing 13, including four children. That chopper dispatched to survey damage from the massive 7.2 earthquake, when it went down. All of the deaths, people who fled their homes. A relative of one of the victims said that the entire town was without power. People were planning to sleep up there. Friday's earthquake left nearly a million homes in Mexico City without power, and south of there at least 50 homes were damaged, but authorities had said there were no fatalities until the tragic chopper crash. Mexico is still recovering from another large quake last September that left hundreds of people dead, and caused widespread structural damage. Tonight, we still do not what caused that helicopter to crash. That part of the investigation continues. Tom. Marcus, thank you.

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