Fans with tickets for one day only were left with only seeing eight minutes of on-track action after FP1 was abandoned following Carlos Sainz striking a water valve cover that had become dislodged on the Strip after the concrete frame around it failed due to the forces underneath cars running over it.
It destroyed the monocoque, Internal Combustion Engine, Control Electronics and Energy Store of the Ferrari, as Esteban Ocon also suffered a chassis change after impacting the cover.
FP1 was abandoned with lengthy track inspections taking place to prevent a similar occurrence with the drains - which has happened on street tracks such as Monaco and Azerbaijan previously.
The second practice session was then delayed by two-and-a-half hours until 02:30 local time, but fans were sent home at 01:30 after security staff 'timed out' on their work hours.
A statement was released shortly after FP2 ended at 04:00 local time on Friday morning, but no mention of a potential refund or apology has been forthcoming by the promoter, with fans only due to be present being offered a $200 dollar voucher for use in the official merchandise stall.
Viewed by others:
"There is no higher priority at a Formula 1 race than the safety and security of drivers, fans and staff alike," read the message sent to all-such affected ticket holders.
"Following last night’s incident involving a water valve cover, the Las Vegas Grand Prix, F1 and the FIA were faced with the difficult decision to close the fan zones prior to the beginning of Free Practice 2.
"We appreciate your patience while we remedied the situation. This was not a decision we took lightly. As a thank you for your support, we would like to offer you a $200 voucher to the Las Vegas Grand Prix Official Shop.
"With a full round of practice successfully completed, we look forward to providing a safe and entertaining race weekend for all."
In an earlier statement, Las Vegas Grand Prix CEO Renee Wilm explained the thinking behind fans being asked to leave at 01:30.
"First, we were concerned about our public safety and security officials who had been in service for a long time and who are being asked to work for the next three nights," she said.
"We thank Clark County’s MetroPolice Department, Department of Public Works and other public safety officials for their incredible support during the event and also as we re-opened the track early this morning.
"Second, we were concerned about our transportation employees who are responsible for driving our fans back to hotels. By Federal law, they were bumping up against the amount of time they can legally and safely drive buses.
"Finally, our hospitality staff needed the ability to clean and resupply our guest areas to ensure that the fan experience is optimal for everyone over the coming days.
“We know this was disappointing. We hope our fans will understand based on this explanation that we had to balance many interests, including the safety and security of all participants and the fan experience over the whole race weekend.
"We have all been to events, like concerts, games and even other Formula 1 races, that have been cancelled because of factors like weather or technical issues.
"It happens, and we hope people will understand."