Hackers shut down alarms, cut off communications and super pressurized the crude oil in the line which resulted in an explosion.

The explosion caused more than 30,000 barrels of oil to spill in an area above a water aquifer and cost BP and its partners $5 million a day in transit tariffs during the closure, according to communications between BP and its bankers cited in “The Oil Road,” a book about the pipeline.

Some of the worst damage was felt by the State Oil Fund of the Republic of Azerbaijan, which lost $1 billion in export revenue while the line was shut down, according to Jamala Aliyeva, a spokeswoman for the fund.