Learn Spanish (Spain): Durante la escala, se nos ha perdido el equipaje. - During the layover, our luggage got lost.

This is the accidental se construction. Instead of saying hemos perdido el equipaje (we lost the luggage), which sounds like you are taking direct blame, Spanish uses se nos ha perdido (it got lost to us) to show it was an accident and completely out of your control.

In se nos ha perdido, what is the subject of the verb?

The subject is actually el equipaje (the luggage). In this construction, the thing that gets lost or broken acts as the subject, which is why the verb ha perdido is in the third-person singular. The pronoun nos just shows who was affected by the accident.

Why is the verb singular (ha perdido) when multiple people (we) lost the luggage?

The verb must agree with the thing being lost, not the people affected. Because el equipaje is a singular noun, the verb is the singular ha perdido. If you lost multiple suitcases (las maletas), it would change to the plural: se nos han perdido las maletas.

Wait, does escala mean scale here?

While escala can mean a scale on a map or a musical scale, in travel contexts it means a layover or stopover during a flight or journey.

Could I put el equipaje before the verb instead of at the end?