My senior citizen parents are travelling from Minneapolis to Bangalore . Minneapolis to Chicago by American airlines. They have to change their terminals from Terminal 3 to Terminal 5 in O'hare International airport an re check in their baggage. From Chicago to Abu dhabi and from Abu dhabi to bangalore by Etihad airlines.Can someone tell me would they get some assistance in Chicago to transfer and recheck in their baggage. And the end to end journey is booked through single ticket.Thanks in advance.