BOARDMAN, Ohio — Barack Obama expressed hope yesterday that the lessons learned from Hurricane Katrina three years ago would help to protect the Gulf Coast from Hurricane Gustav this time. His running mate, Joe Biden, urged people to pray that the levees in New Orleans hold.

Obama and Biden visited a diner in this Youngstown suburb, an area that Sen. Hillary Rodham Clinton carried during her failed presidential bid. Trying to connect with those who are economically struggling, the Democratic candidates and their wives chatted with diners and told reporters that a properly orchestrated evacuation would be key to protecting the Gulf Coast.

"It wasn't last time, and hopefully we've learned from that tragedy," Obama said as he left the diner and headed to a memorial service for the late Rep. Stephanie Tubbs Jones, the first black woman to represent Ohio in Congress. She died Aug. 20 from a brain hemorrhage caused by a ruptured aneurysm.

Obama and Biden planned another joint appearance later yesterday in the Columbus area.

Northeast Ohio, a Rust Belt region where the economy has struggled, supported Clinton's presidential bid back in March. Obama carried the Democratic stronghold of Cuyahoga County, with Cleveland, but lost 83 of 88 counties.

Since then, Obama has been a frequent visitor in the area, trying to connect with the white, working-class voters who have eluded him so far.

Biden said the Gulf Coast appears better prepared for a major hurricane this time than it was for Katrina, which left New Orleans submerged. He said it appeared officials had learned from Katrina, and he praised moves to make major highways one-way routes out of the threatened areas.