Taking the A train

Yesterday, I'd taken the 7:02 train to Penn, so I had time to burn. I took the A train, which only has 4 stops to Chambers Street. I young girl, maybe 8 or 9 was sitting on my left. She got up at West 4th street and unwittingly dropped her little purse. I scooped it up and got her attention before she left the car. A "thank you" would have been nice.