Q train needs window repair...

I was on a Manhattan bound Q train from Brooklyn this morning just after 9:30am. Right before we crossed the Manhattan Bridge, the window in the door between cars fell out and landed between the cars. The gentleman that had been leaning on the door slowly moved further into the car and the rest of us continued reading/sleeping, etc.

I took down the car number and reported it to the transit clerk at Union Square.

Has anyone ever witnessed the subways fall apart like this? It wasn't scary in the sense that I felt endangered, but I wonder what other disrepair is waiting to happen at any moment when I ride the trains...