A vegetation fire that broke out late Thursday night at Coal Oil Point west of Isla Vista and UCSB was 70 percent contained as of Friday morning, according to the Santa Barbara County Fire Department.

The Tank Fire, as it’s been dubbed, had burned at least 20 acres as of 7 a.m., said fire Capt. David Sadecki.

Crews expected to have full containment by 6 p.m.

One structure was threatened by the blaze, which was reported at about 9:41 p.m. Thursday near Seaway Drive and Slough Road. 

The structure, on the fire’s east side, was evacuated as a precaution, Sadecki said.

The fire also was near the Devereux Foundation campus and Venoco Inc. oil tanks, but neither was threatened, Sadecki said. 

Downed power lines and possible use of fireworks were reported in the area, but the cause of the blaze remained under investigation, Sadecki said. 

“We do have a suspicious subject in the area and law enforcement is dealing with that,” Sadecki said. 

County Fire had seven engines and two water tenders on the scene shortly before midnight. They were assisted by the Santa Barbara City Fire Department, Vandenberg Fire Department, UCSB Police and the Santa Barbara County Sheriff’s Department. 

Noozhawk news editor Giana Magnoli can be reached at gmagnoli@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.