fetch() returns a 'Deferred Object' see: http://api.jquery.com/category/deferred-object/
it's not really like try{} catch{}, but you can use .always() method to bind a callback which will be executed after the request is done (no matter if it was successful or not)
like so.
var doSomething = function () {
//will run after fetch() request is finished
};
collection.fetch().always(doSomething);
similarly, instead of passing success
or error
callbacks to fetch()'s options, in general it is encouraged to chain .done(), .fail(), or .then() methods to deferred methods(fetch, save...etc)