In the predawn darkness, a team of scientists climbs the slope of Mexico's Popocatépetl volcano, one of the world's most active and whose eruption could affect millions of people. Its mission: figure ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. POPOCATÉPETL VOLCANO, Mexico (AP) — In the ...