Imagine rafting down the Colorado River for 25 days, with no contact from the outside world, only to return and discover that a deadly pandemic has swept the planet while you were off the grid."The first message I get is from my mom and she says, you need to call me now," said Mason Thomas, of Sacramento, California. Mason and his girlfriend Kate Condino, were among a group of more than a dozen friends who left civilization in mid-February to raft 280 miles through the Grand Canyon with no cellphone service or outside contact.