“ExceptionYieldYield” (Problem)

At what point will happen Exception?

public static IEnumerable<int> GetSmallNumbers()
{
  throw new Exception();
  yield return 1;
  yield return 2;
}
void Main()
{
  var numbers = GetSmallNumbers();
  var evenNumbers = numbers.Select(n => n * 2);
  Console.WriteLine(evenNumbers.FirstOrDefault());
}

Solution