Sainz's Ferrari crawled to a halt between the Bellagio and Paris hotels on the Strip, his onboard camera showing that his Ferrari had apparently been rendered immobile by a bump in the road.
TV cameras later appeared to show heavy damage to the front part of Sainz's floor, with the FIA confirming that a loose manhole cover was understood to be the culprit.
FP1 will hence not be restarted to ensure fixes to the circuit, which will include further inspection of the other drains around the circuit and further spot-welding of those deemed to be at risk of causing further incident.
"Following inspection, it was the concrete frame around a manhole cover that has failed," the FIA explained in a statement.
"We now need to check all of the other manhole covers which will take some time - we will be discussing with the local circuit engineering team about the length of time it will take to resolve and will update with any resultant changes to the schedule."
Of the other drivers affected, Esteban Ocon will receive a new chassis having also hit the drain cover along the Strip during the red flag period.
With no other support categories, it is possible that the FIA could choose to extend either the FP2 or FP3 sessions to make up for the loss of running.
This echoes the abandonment of the opening practice session at the 2019 Azerbaijan Grand Prix, when George Russell's Williams sustained heavy floor damage after hitting a loose drain cover on the run to Turn 3.
Russell had to miss FP2 during that weekend as he was issued with a new chassis, and the errant drain cover was understood to have been an anomaly compared to the others around the circuit.
Haas also received compensation for a drain-related incident in 2017, as a "welding failure" on a drain at Sepang pitched Romain Grosjean into a crash in the Malaysian GP FP2 session.
Amid the drivers' initial laps around the Las Vegas street circuit, the times quickly tumbled as the drivers became acquainted with the layout.
Valtteri Bottas launched the first timed lap with a 1m50.227s, but the benchmark swiftly fell as several drivers lowered the bar - Charles Leclerc ending the first five minutes with a 1m44.019s.
Leclerc's team-mate Sainz then produced the unwelcome hiatus in the early reconnaissance laps, which stopped the session after 20 minutes.
TV cameras appeared to show heavy damage to the front part of Sainz's floor, with a drain cover understood to be the cause of the damage, with FIA stewards Garry Connolly and Derek Warwick checking the damage to Sainz's car.