Air India Boeing 777 returns back to EWR?

I saw Air India Boeing 777 depart around 9:10pm last night 3-6-07 at EWR and around 10:30 or later it returned back to EWR landing on 4R. Then i saw it being escorted to Terminal B by firetrucks and i cought the tail of that Air India as i was catching a Singapore Airbus A340-500 getting ready to depart. If you look the Singapore aircraft the Air India can been seen as it is heading to the terminal but i didnt get the firetrucks.
http://i116.photobucket.com/albums/o...r/000_4056.jpg
I understand that it was an emergency landing. But does someone have any idea what happened to that flight?