ATLANTA (AP) — Colonial Pipeline plans to shut down a key line that supplies gasoline to the South due to storm-related refinery shutdowns and Harvey's effect on its facilities west of Lake Charles, Louisiana.

The Georgia-based company expects to shut off the line Thursday, the company said in a statement. Colonial had already closed down its other main line, which transports diesel and aviation fuels.

The pipeline, a crucial artery in the nation's fuel supply network, provides nearly 40 percent of the South's gasoline.

In September 2016, a leak and gas spill in Alabama that closed the Colonial Pipeline led to days of empty gas station pumps and higher prices in Alabama, Georgia, Tennessee and the Carolinas.

Gasoline prices have been on the rise even before the pipeline shutdown. Harvey's devastating strike on the Gulf Coast has prompted one of the summer's largest one-week price surges, AAA reported.

Among the reasons: About one-quarter of the Gulf Coast's oil refining capacity was taken offline, according to the Oil Price Information Service.

The storm also prompted at least eight Texas refineries to shut down, according to AAA. Nearly one-third of the nation's refining capacity is along the Gulf Coast from Corpus Christi, Texas, to the Lake Charles area.

Colonial Pipeline has not indicated how long it expects the closure to last, saying it will know more when workers can evaluate its facilities.

Half of the 26 refineries that connect to Colonial's pipeline system are between storm-ravaged Houston and Lake Charles, which is just east of the Beaumont-Port Arthur metro area.

"Once Colonial is able to ensure that its facilities are safe to operate and refiners in Lake Charles and points east have the ability to move product to Colonial, our system will resume operations," the company said in its statement.

The Colonial Pipeline runs from the Houston area to the New York harbor and includes more than 5,500 miles of pipeline, most of it underground.