With teams limited to 13 sets of tyres for a Grand Prix weekend, Haas' Russian Grand Prix got off to the worst possible start when two sets of Kevin Magnussen's tyres were damaged in a fire overnight.
It's understood the fire, which was discovered by night guards on duty at the Sochi track, was caused by a faulty control box for the tyre blankets.
"We don't know if it was the cable or the tyre blanket, because everything is burned," said team boss Guenther Steiner. "So we will investigate.
"The good thing was the night guards were around and they caught it," he added. "I wouldn't say early, but they caught it, but there could have been a lot more damage if they hadn't caught it.
"All the night guards worked together to extinguish it and did a great job, and I want to thank them for that."
Asked if the fire might have been caused by turning up the heat of the blankets, which would be a breach of the rules, Guenther insisted: "No, they were on stand-by. They were connected. We don't know if it was the cable or what it was."
"There was fire in the Haas garage," confirmed Pirelli's Mario Isola. "It was because of malfunctioning of the blankets, or the control unit of the blankets and two sets of tyres have been damaged. We have already replaced them with the agreement of the FIA but nothing special.
"Teams are allowed to keep the tyres in blankets at a maximum temperature of sixty degrees for the slick tyres, so usually they keep the blankets on during the night and they are allowed to do that. Then it happened. Luckily somebody was able to extinguish the fire very quickly so the damage was very limited."