Lake Tahoe is "the fairest picture the whole earth affords," Mark Twain once wrote. Its crystal blue waters, surrounded by stunning snowy mountains, define one of California's crown jewels as an American landmark. It attracts 3 million skiers, boaters, campers, hikers and other visitors each year. But it could look very different in 100 years. Climate change could profoundly affect the Tahoe area, scientists say, taking the snow out of the mountains and the blue out of the water.

The pipe that fed a huge fire at Chevron's Richmond oil refinery in August appears to have been punctured from the outside, possibly by company firefighters trying to get at a small leak before the blaze ignited, investigators said Thursday. The 40-year-old pipe had already been weakened by the heavy sulfur content of the crude oil being pumped through it, according to a draft metallurgical report on the fire that was prepared for federal and state investigators.

San Francisco Giants pitcher Sergio Romo is facing a misdemeanor summons in Las Vegas alleging he violated airport rules after being detained by authorities at McCarran International Airport on New Year's Day. The federal Transportation Security Administration issued a statement Thursday saying Romo failed to provide proper identification at a document checkpoint and engaged in a dispute with TSA officers about 8:30 a.m. Tuesday.

Conservative America can't get enough of the story about liberal former Vice President Al Gore selling the Current TV network he co-founded to Al Jazeera. Or, as Fox News commentator Ann Coulter described it - "a foreign company that hates America." Tweeted Coulter Thursday: "Gore sold Current TV to Al Jazeera for $500 million. Al Qaeda could only come up with $400 million."

Police extolled Oakland's soon-to-be expanded gunfire detection service Thursday for helping officers arrest a gunman earlier this week and retrieve a military grade assault weapon -- the same variety used by the department's SWAT Team. As part of an enforcement operation targeting celebratory gunfire on New Year's Eve, a team of nine officers raced to the 2200 block of 84th Avenue where Oakland's ShotSpotter system recorded multiple gunshots at 10:31 p.m. Monday.

In a move expected to shake up health care labor battles statewide, the powerful California Nurses Association announced Thursday that it will affiliate with the National Union of Healthcare Workers in fights with major health systems over wages, benefits and patient care issues. CNA also agreed to use its 85,000 members and considerable resources to help NUHW in its campaign to defeat a large rival, the Service Employees International Union-United Healthcare Workers West, in an upcoming election for the right to represent 43,500 Kaiser Permanente service and technical workers.

They are sudden, they are remorseless and they can suck their victims into the sea to an almost certain death. Summoned by wind and tide, these "sneaker waves" hurl themselves far beyond the foam line on the beach then forcefully go in reverse. In the past week alone, they are blamed for the drowning deaths of three people on Bay Area beaches.

Even on sunny days travelers flying to and from San Francisco International Airport may see extra delays in 2013. That's because the airport will be temporarily shutting down some runways in January, April and June as part of a multiyear construction project. Travelers on shorter, West Coast flights could see their departures pushed back by 30-45 minutes, airport spokesman Doug Yakel said.</blockquote

It's comforting to know that when one door closes, another one opens. Especially if that door leads to a $300 million new space. Nevertheless, thousands crowded the San Francisco Exploratorium on Wednesday as the famous science museum celebrated its final day at the Palace of Fine Arts, its home for the last 43 years. The museum will close for a three-month hiatus as it prepares to open at its new location on Pier 15.