(KRON) -- A wildfire ignited east of Vacaville in Solano County and rapidly grew to nearly 900 acres Friday afternoon, Cal Fire officials said. The wildfire, named the Hay Fire, triggered evacuation orders for zones OKL-E176 and OKL-E203. The blaze ignited near the 6200 block of Hay Road around 1 p.m. during a Red Flag Warning and windy weather. As of 4:45 p.m., firefighters reported that the Hay Fire was 20 percent contained. Cal Fire's Sonoma-Lake-Napa Unit is investigating to determine what caused the wildfire. This is a developing story. Stick with KRON4 for more updates.