Braving a bitterly cold morning, an informal parade of politicians, schoolchildren and bicyclists paid their last respects yesterday to a decrepit Philadelphia landmark.

The South Street Bridge, which has spanned the Schuylkill since 1923, was officially closed to traffic at 10:39 a.m. to be prepared for demolition.

For many who came to cross one last time, it was a bittersweet moment.

"We just wanted to say goodbye," said State Sen.-elect Larry Farnese, who walked with a group of about 20 community organizers and ward leaders. "It's been a part of the community for so long."

The end was long in coming. Highway engineers signed the death warrant for the 85-year-old structure more than two decades ago when they declared it "structurally insufficient."

Since then, chunks of concrete have sporadically crumbled from the 300-foot span onto the Schuylkill Expressway below. In 2007, trucks and buses weighing six tons or more were banned from crossing.

The reconstruction project will take two years and cost about $67 million.

A nearby private school took advantage of the bridge's last hour, turning it into a teaching moment.

Dozens of first and second graders from the Philadelphia School tromped over the bridge shortly after 9 a.m. to take a close look at the pockmarked structure.

Students at the school, at 25th and Lombard Streets, will have a front-row seat to the bridge's demolition and reconstruction, said Amy Vorenberg, the head of school.

"We plan to use the events at the bridge to inform the science and art curricula," Vorenberg said. "It's an exciting moment for the city."

A group of bicyclists pedaled across for a ceremonial last ride as the 76 children hustled back to the warmth of their classrooms.

Many of the bike riders expressed mixed feelings.

"My five-minute-and-fivesecond commute is shattered," said Michael McGettigan, 54, who owns Trophy Bikes in University City.

McGettigan, who piloted his Dutch-made Bakfiets cargo bike across the bridge, said it would take him twice as long to reach his shop at 31st and Walnut Streets from his home on South Street.

Like most residents of Southwest Center City, McGettigan will take the detour over the Walnut Street bridge.

Russell Meddin of Bike Share Philadelphia was one of the last of about 20 people to officially ride over the South Street Bridge.

"It was fun, windy and chilly, a very good end for something good to come," Meddin said.

John Boyle, the last rider across the span, mused as he pedaled to West Philadelphia.

"I was thinking about the new bridge and how much better it will be," Boyle said, noting that the new structure would have designated bike lanes.

"I think it's going to be a big hit," he said.