What happened
Following landing at San Juan, the aircraft was parked at the customs area before being towed to Gate 15 for loading. The push-back procedure required the crew to taxi to the general aviation parking area to turn around before proceeding to Runway 8 for departure. When cleared for takeoff, winds were from 160 degrees at 11 knots, gusting to 22 knots. Approximately 120 knots into the takeoff roll, a loud rumbling sound occurred and rapidly increased, followed by aircraft vibration. At approximately the V1 speed of 141 knots, the captain rejected the takeoff using maximum braking. Unable to stop on the remaining runway, he angled the aircraft toward the safest available area. The flight engineer's back was injured as the aircraft hit the REIL system. The aircraft stopped with its nose in a lagoon. Due to trees, water, aircraft attitude, and one accidental disarming, only 4 of 8 emergency slides were used.
The investigation
A lab analysis indicated that the #7 tire had failed due to low inflation, most likely from FOD. During the abort, its companion tire failed from overload. Black marks on the taxiway revealed the #7 tire started losing pressure while the aircraft was taxiing.