def METHOD_NAME(topic_id):
    try:
        query = (
            flask.g.session.query(models2.User.email)
            .join(models2.UserTopic)
            .filter(models2.UserTopic.topic_id == topic_id)
        )
        return [um[0] for um in query.all()]
    except dci_exc.DCIException:
        return []