On October 29, 2012 Hurricane Sandy descended upon the New York and New Jersey coastlines. Among the storm’s many casualties were some of the area’s cellphone towers, leaving millions of residents stripped of both electrical power and their usual cell phone service. “I was thinking, ‘Is there any way to make cell phones communicate, so even in the worst case scenario like Sandy, when you have no power or Wi-Fi, you can still communicate?’” Daniela Perdomo says. “The only thing that does that is Bluetooth, and for that you have to be within 20 feet, so you might as well just speak loudly. We figured out that the only way to do that was an external piece of hardware.” By November 2—less than a week later—Perdomo had sketched out a plan for goTenna, a gadget that could have given people stuck without service the ability to use their phones again.