Missed base- FED rule

[robertl]

I'm looking for confirmation on a call made in a 14yr old league. On a base clearing double the umpire declared the last runner to score out saying he missed 3rd base. I thought the other team had to appeal that play yet the umpire said FED rules allow him to declare the runner out when he sees it without an appeal from the other team. Is this true? I don't have a rule book and can't llok it up.

Thanks