A ransomware cyberattack has forced the temporary shutdown of Colonial Pipeline a major gas pipeline that supplies 45 percent of all fuel consumed on the East Coast. The attack highlights heightened concerns over the danger to major U.S. infrastructure.

The cyberattack against Colonial Pipeline began at 7:00 p.m. on Friday night, according to a Federal Emergency Management Agency report.

Colonial Pipeline, which runs from Houston to Linden, New Jersey, transports about a million gallons of fuel daily.

However, the hackers actually began their hacking against the company a day earlier, stealing a large amount of data before locking computers with ransomware and demanding payment, according to a report from Bloomberg.