Sadness And Worry After 2 Men Connected To Butterfly Sanctuary Are Found Dead

A guide walks past a sign asking for silence near the winter home of monarch butterflies in El Rosario reserve near Ocampo, Michoacán, in Mexico on Friday.

Millions of monarch butterflies migrate to the mountains of Mexico each winter. Authorities are now investigating the apparent murders of an activist and tour guide at the Michoacán reserve.

(Image credit: Rebecca Blackwell/AP)