From the Denver Post:
Alyssa Heberton-Morimoto, a Masters student mapping for the Colorado Geological Survey, was murdered while waiting for her field partner to meet her for lunch. I'm horrified. Yikes, that poor woman and her family. And her poor field partner, who heard the screams over her radio, and who hitched a ride with the murder suspect because her car keys were missing.
I've been in the habit of mapping in pairs - I've worked in grizzly country, and there are a lot of things that can happen alone and far from help. But most of them are things like sprained ankles and falls on steep slopes and, occasionally, bears or mountain lions. But murder. Yikes.
My male colleagues regularly do field work alone. I don't. And perhaps I'm wise, though significantly less productive.
(On the other hand... an acquaintance of mine was murdered, along with her female companion, on the Appalachian Trail more than 10 years ago. Two might not be enough for real strength in numbers.)