Update: Tragically, one of the skiers, Rob Williams, was not able to be saved. Our thoughts go out to his family.

Yesterday, a group of technology entrepreneurs from the UK on a skiing vacation in the Swiss Alps (Verbier) lost two of their party around 4 PM CET. Other members of the group put out a request on Twitter in order to learn the numbers of their mobile phones, so they could use the signals to track them down.

According to follow-up tweets, one person (Jason) was rescued using a combination of GPS, Google Maps to determine longitude and latitude, and the signals returned from his iPhone, but another one (Rob) was still missing as the two had apparently been split up. It’s been 7 to 10 hours since the last Twitter messages at this point, so unfortunately we can only hope and not confirm if Rob has been found by now.

Below are a number of screenshots with Twitter messages from some of the group, including Alex Hoye (CEO of digital marketing agency Latitude, Michael Acton Smith from Mind Candy, Joshua Marsh and Hermione Way (TechFluff.tv) Michelle Dewbs (winner of The Apprentice).

Let’s hope everything is alright. We’re frantically tracking Twitter to learn more, and we’re not the only ones.

(Hat tip to Google Maps Mania)