Our fUSAirlines flight out of Westchester was delayed over 1 hour this morning due to mechanical problems. When we arrived in Philadelphia we were told our USAir flight to Punta Cana would not wait for us. We rushed to the get and got there a few minutes late and we're told gate was shut. We were flying 1st class. So we are stuck in Philadelphia with no luggage and hopefully when we get to Punta Cana tomorrow we will find our luggage. Don't understand why they did not hold the plane. It was their fault we were late!