The City of Vallejo has temporarily closed the Mare Island Shoreline Heritage Preserve for safety concerns after two fires on south Mare Island this week.
The preserve is closed to all but emergency personnel, the Vallejo City Manager's Office said Friday.
A 10-acre fire that started around 3:05 a.m. Wednesday is believed to have started when someone cut five power poles with an electric Sawzall.
Two of the poles were nearly sawed in half causing the poles to lean and power lines to fall, the Vallejo Fire Department said.
A 40-acre fire started around 11:30 a.m. Thursday while firefighters were extinguishing hot spots from Wednesday's fire, the Vallejo City Manager's Office said.
A sudden increase in wind speeds caused a flare-up on a hot spot in the fire perimeter resulting in a five-alarm fire that was contained around 8 p.m. Thursday.
The flames burned a fence outside a historic Navy cemetery but caused no damage to the cemetery itself.
The only structures threatened by the fire were abandoned Navy storage buildings, Vallejo Fire Engineer Kevin Brown said.
Wind gusts up to 40 mph caused the fire to jump three roads in the area, Brown said.