Presidential candidates John McCain and Barack Obama are honoring the victims of the Sept. 11 terrorist attacks, paying a joint visit to ground zero. The Republican and Democrat walked down a ramp to the site where the World Trade Center once stood, and threw flowers into a reflecting pool. Cindy McCain and New York Mayor Michael Bloomberg accompanied the two candidates. Obama and McCain greeted family members of the victims. Beforehand, McCain spoke briefly at a ceremony in rural western Pennsylvania. The event was held on a large hilly field close to where United Airlines Flight 93, the third of four airliners commandeered by terrorists, crashed.

President Barack Obama called for tying teachers' pay to students' performance and expanding innovative charter schools Tuesday, embracing ideas that have provoked hostility from members of teachers unions. He also suggested longer school days - and years - to help America's kids compete in the world.

In his first big speech on education, Obama said the United States must drastically improve student achievement to regain lost international standing.

"The future belongs to the nation that best educates its citizens," he said. "We have everything we need to be that nation ... and yet, despite resources that are unmatched anywhere in the world, we have let our grades slip, our schools crumble, our teacher quality fall short and other nations outpace us."

His solutions include teacher pay and charter school proposals that have met resistance among members of teachers unions, which constitute an important segment of the Democratic Party.

Obama acknowledged that conflict, saying, "Too many supporters of my party have resisted the idea of rewarding excellence in teaching