A man died Sunday morning after his sports car crashed into a power pole just north of Riverfront Regional Park near Windsor.

The 2004 silver Nissan Z coupe was traveling south on Eastside Road at a high rate of speed around 8:28 a.m. when the car hit the pole, shearing it completely before slamming into a tree, the CHP said. The severed pole fell into the middle of the road, along with the power lines, blocking traffic in both directions.

The car, which had extensive front-end damage, then caught fire, CHP said. Flames spread to surrounding vegetation, but firefighters extinguished the blaze.

Windsor firefighters declared the driver dead at the scene.

“An ambulance was called but stood by,” said Rincon Valley-Windsor Fire Battalion Chief Aron Levin.

Emelyn Aranda, a booking agent from Windsor, was heading to work at Guerneville’s Russian River Getaways with a coworker when they came upon the crash shortly after it occurred. Aranda said a woman traveling south on Eastside Road asked her to call 911 because she did not have a cellphone.

“I pulled over to the side and noticed a little black smoke coming out of the engine,” Aranda said. “People tried to pull him out, but the driver’s side was against the side of the tree, and they said he was unresponsive.”

As the fire grew, Aranda said, flames set off the car horn, and then spread to the interior of the car and up into the trees.

“People had water bottles ... but no one had a hose or a fire extinguisher,” Aranda said.

“There was really nothing we could do,” she said. “I just want his family to know we tried.”

Robert Hopkins of Hopkins River Ranch, who lives about a quarter-mile north of the park entrance, said when he returned from church at 11 a.m. the power was out and both lanes of the road were closed south of his home.

“There are usually quite a few cyclists on the road,” he said. “But fortunately none were in the vicinity.”

The driver’s identity is being held pending notification of next of kin.

The CHP is investigating the cause of the collision and looking into whether impairment, medical or mechanical issues were factors.

Forestville, Healdsburg and Windsor-Rincon Valley firefighters also responded to the crash.

CHP officials ask anyone who witnessed the collision to call 707-588-1400.

Staff Writer Diane Peterson can be reached at 707-521-5287 or diane.peterson@pressdemocrat.com. On Twitter @dianepete56.