Updated 3:08 PM ET
(CBS/AP) JOPLIN, Mo. - A year after a massive tornado tore through Joplin, reminders of the storm's fury are plentiful from the glaring absence of century-old trees in the city's central neighborhoods to the ghostly shell of St. John's Regional Medical Center.
Residents, hospital workers and politicians gathered across the disaster zone Tuesday to mark the year since the tornado, mixing somber remembrances with steely resolutions to rebuild the battered city, where 161 people were killed.
"It is so fitting to begin this day, this anniversary, by reflecting on our faith as dawn breaks over a renewed Joplin," Missouri Gov. Jay Nixon said at a sunrise service at Freeman Hospital to honor the tornado survivors, medical workers and volunteers who sprang into action after the storm struck. "Scripture tells us that the path of the righteous is like the first gleam of dawn, shining ever brighter till the full light of day."
Many businesses have reopened and homes are being rebuilt, but much remains to be done in this city of 50,000 near the borders of Arkansas, Kansas and Oklahoma. The tornado, packing winds of 200 mph, wiped away entire neighborhoods, destroyed the city's only public high school and a major hospital, and left behind a ghastly moonscape of block after city block of foundations wiped clean of their structures.
Watch a video of President Obama's speech at Joplin High School's graduation ceremony below:
Later Tuesday, city government leaders joined residents, volunteers and state and local politicians for a 4-mile "Walk of Unity" through some of the city's hardest-hit neighborhoods. The afternoon procession started in neighboring Duquesne, where more than one-fourth of the community's 750 homes were destroyed and nine people died. The Joplin portion of the walk begins past a Wal-Mart where three people were killed and 200 survived by huddling together in employee break rooms, bathrooms and other designated safe zones.
The walk will conclude with a moment of silence at Cunningham Park at 5:41 p.m., the moment the tornado struck. The city park, which is across the street from what is left of the St. John's hospital, has been rebuilt.
The medical center hasn't yet been torn down because it sits atop the mining tunnels that made Joplin an early 20th century boomtown. The hospital has been operating out of a succession of temporary facilities while construction continues at its new permanent location, where it will reopen under the name Mercy Hospital Joplin.
The city held the first of three groundbreaking ceremonies Tuesday for new schools in the shadow of St. John's former home on land donated by the Sisters of Mercy Health System. An elementary school will be built at the site to replace two that were destroyed. "The sound of hammers has replaced the sound of sirens," said C.J. Huff, Joplin's school superintendent.
A community theater where three people died after a Sunday matinee performance will be rebuilt nearby. A groundbreaking ceremony was planned for later Tuesday for Joplin High School, which was also destroyed.
"It's been a roller-coaster type year. Extremely high highs and lots of low lows." said Debbie Fort, the principal of Erving Elementary School, which has been operating out of temporary facilities and which will be the name of the new school.
"It's important that we take a moment to reflect and remember," she said. "But it's a new chapter in our lives. This really signifies our future, the future of Joplin."
Watch Ben Tracy's interview with Joplin High School graduate Quinton Anderson below:
CBS News correspondent Ben Tracy interviewed one of the graduates of Joplin High School, Quinton Anderson, who lost both his parents in the disaster.
"I'm one of those people that doesn't cry when people are around, so when I was alone at nights, I would cry,"said Anderson. "It was just kind of like the realization, like, I'm an orphan now, and I just have my sister.
"I miss my mom's smile and I miss my dad's goofy laugh. They were kind of a goofy couple, but they loved each other."
While many of Tuesday's events looked back, there was talk of moving on as community leaders look at what's bound to be yearslong recovery.
Insurance policies are expected to cover most of the $2.8 billion in damage from the storm. But taxpayers could supply about $500 million in federal and state disaster aid, low-interest loans and local bonds backed by higher taxes. Almost one-fifth of that money was paid to contractors who hauled off an estimated 3 million cubic yards of debris.
In January, elected officials and other members of a 45-person recovery committee endorsed a long-term recovery plan that calls for the creation of four new business districts that would allow residents to live and shop nearby and a unified approach to rebuilding that ensures new construction meets certain design standards.
In March, the city hired Wallace Bajjali Development Partners, of Sugar Land, Texas, as its "master developer" to oversee the rebuilding plan.
Tuesday's events were also expected to attract some of the more than 130,000 volunteers who descended on southwest Missouri from across the country to help out. That group includes a contingent of bicyclists who left New York City's Central Park nearly three weeks ago on a Cycle for Joplin fundraising ride organized by a group of former Joplin residents known as the Joplin Expats.