Martin Bertogg, head of catastrophic perils at Swiss Re, said that the industry had been challenged by what is known as “secondary perils.” That is, while the insurance industry has historically done a good job of modeling relatively rare but potentially devastating events such as earthquakes and hurricanes, it’s battling to keep up with risks posed by snow storms, hail, tornadoes and wildfires. Those used to cause relatively minor damage but are increasingly morphing into something more costly. And that is a problem for companies, since many Americans have coverage for such events.