Charlie Whiting says the loose drain cover that caused Romain Grosjean to suffer a reported 17G crash at Sepang was a freak incident.
The Frenchman brought out the red flags in Friday's second practice at the Sepang circuit when a loose drain cover shredded his tyre.
Grosjean hit the wall at a reported 17Gs, which caused significant damage to his VF17. Thankfully he was unhurt.
Explaining the incident, F1 race director Charlie Whiting told Motorsport.com: "One of the drain covers, which measures about half a metre long and 30cm wide and heavy cast metal, came up.
"There are quite a few of them around the circuit and at this particular place, there are five at intervals on the outside of T12.
"That's a high-G corner with massive load being put through, and what we have found is some of these drains are bolted down and some are welded down.
"Welding is perfectly acceptable. I suspect the bolts have probably broken and rather than replace the whole thing, they've thought, 'we’ll weld it down'.
"Quite evidently, the welds just gave up. It’s as simple as that really. No one saw that coming."
Asked if he believed it was a freak incident, he replied: "Yes, that's exactly what it was."
And while Haas spent the night fixing Grosjean's car, Whiting and the circuit engineers looked at every drain to ensure that there would be no repeat of Friday's accident.
"I’m not sure how many there are – we’ve seen a few, but not that many," he said. "They will grind all the paint away, they will grind the welds back a bit and they will re-weld them.
"That’s all we can do. The drains are not the latest technology."