LAKE TAHOE, Calif. — Two skiers died after colliding with trees in separate accidents last week at a pair of Tahoe-area resorts.

On Friday, Lindsay Allen Van Why, 43, of Belmont, Calif., was skiing in the Cascade area of Northstar California. Van Why — who was not wearing a helmet — suffered severe head and facial trauma and was killed after hitting a tree, Placer County Sheriff’s Office Spokeswoman Dena Erwin said Wednesday.

Last Thursday, the body of Santos Constantine Martins Bezerra, 18, of Sao Bernardo, Brazil, was found at Sugar Bowl Ski Resort. Erwin said Bezerra, a seasonal employee at the Donner Summit resort, struck a tree while skiing the previous day.

Bezerra also was not wearing a helmet, Erwin said.

“We encourage people to wear helmets,” Erwin said. “It doesn’t guarantee your safety, but it certainly couldn’t hurt. We also urge people to use caution and not be at high speed, especially in wooded areas.”