When 200 million metric tons of rock tumbled down a remote Southeast Alaska mountain in October, nobody was around to see it. But thanks to a beefed-up seismic network and a new system that can distinguish landslides from earthquakes, scientists knew it had happened.

The victim, identified as 28-year-old Alexander Hellweger, was part of a group of eight friends from Italy and Belgium vacationing in Alaska.

DOT spokesperson Shannon McCarthy said the weather this week -- alternately freezing and thawing -- was likely the culprit.