Ford Motor Co. is warning of significant damage wreaked by a tornado in South Carolina this week that knocked out a BorgWarner Inc. auto parts plant supplying a key component for the automaker’s most profitable models.

The Seneca, S.C., parts factory makes transfer cases, an important component of four-wheel-drive systems that Ford uses in its F-150 pickup, its biggest moneymaker, as well profitable SUVs such as the Explorer and Lincoln Navigator, the automaker said Friday in a securities filing.

“We do not have sufficient information to estimate when the facility will be back online or whether, or the extent to which, this incident will impact our plans to resume production of four-wheel drive and all-wheel drive vehicles,” Ford said.

BorgWarner’s plant, one of its largest drivetrain manufacturing facilities, was struck by a tornado on April 13 and the company said it’s still assessing the extent of the damage. “Currently, the time to resume operations, partially or in full, cannot be estimated,” the parts maker said in its own filing Thursday.

Ford’s North American factories have been shut since mid-March due to the coronavirus pandemic. When the automaker initially sought to restart facilities this month, it planned to first resume production at plants making lucrative pickups and SUVs. But after push back from the UAW, Ford canceled that plan and now says it will open plants sometime in the second quarter, which could be as early as next month.

With its factories shuttered, the automaker lost $2 billion in the first quarter and burned though about $8 billion this year through early April. Ford now is seeking to raise $8 billion in a junk bond offering.