B777 FLT CREW RETURNS TO GATE AFTER MAIN GEAR TIRE LOSE PRESSURE AND IS INFORMED BY ARPT AUTH THAT TWO TAXI LIGHTS HAVE BEEN BROKEN ALONG THEIR ROUTE.

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DURING NORMAL TAXI OUT FOR TKOF; GOT TIRE PRESSURE EICAS MESSAGE. #4 TIRE RAPIDLY LOST PRESSURE. RETURNED TO GATE. DURING SUBSEQUENT WALKAROUND; GENTLEMAN FROM ARPT MAINT INFORMED ME THAT 2 TXWY LIGHTS WERE SMASHED ALONG OUR TAXI RTE AND DID WE FEEL ANYTHING ON TAXI OUT. I BELIEVE WE DID NOT CAUSE THE DAMAGE BUT MAY HAVE UNWITTINGLY TAXIED OVER SOME OF THE DEBRIS CAUSING OUR FLAT TIRE. INSPECTION OF THE TIRE REVEALED NO EMBEDDED GLASS ON ANY TIRES AND 1 SMALL PUNCTURE ON TIRE #4. SUPPLEMENTAL INFO FROM ACN 780001: THE SYNOPTIC CAME UP ON THE SCREEN AND WE SAW THAT OUR #4 TIRE WAS INDICATING LOW PRESSURE. WE RETURNED TO THE GATE AND; UPON INSPECTION OF THE TIRE; MAINT FOUND A PIECE OF FOD IMBEDDED IN THE TIRE. ONLY TIRE #4 SHOWED DAMAGE BUT BOTH #3 AND #4 WERE CHANGED PER PROC. FO WAS APCHED BY AN ARPT EMPLOYEE ON THE RAMP AS TO WHETHER WE FELT ANYTHING DURING TAXI. NEITHER I NOR FO RECALLED ANYTHING ABNORMAL AS TO THE TAXI OUT. WE HAD A JUMPSEATER AS WELL WHO NOTED NOTHING OUT OF THE ORDINARY REGARDING THE TURN.