This is a pretty absurd thing to say. Natural or accidental deaths are different than planned attacks. There is no shortage of murderous, suicidal people. If you made it easier for them, more of them would go for it. The 3 successful attacks on 9/11 contributed something like an extra 20% to the US murder rate. That’s not insignificant.

Also, we do spend an enormous amount of money on safety in the US. Why do you think the absolute cheapest new cars in the US are two to four times as expensive as new cars in countries that don’t have the same kind of safety standards (e.g. Mexico or India)? And because of the tort system, businesses spend untold amounts of money making their facilities and products safer in general.