Missouri Gov. Jay Nixon has declared May 29 an official State Day of Prayer and Remembrance, one week after a tornado struck Joplin, Mo., a city of 50,000, killing at least 125 and leaving 156 people still unaccounted for.

According to the governor's website, he and the local clergy have also organized a memorial service for the victims. President Barack Obama will be attendance.

In the most trying times of disaster, grief and loss, Missourians come together to provide support, strength and assistance, Gov. Nixon said in his proclamation Friday. During this day of prayer and this memorial service, I invite all Missourians to pause and remember their neighbors and draw upon the resources of their faith in the support of their fellow Missourians.

The service will be held at 2 p.m. Sunday at the Taylor Performing Arts Center on the campus of Missouri Southern State University.

Both Gov. Nixon and President Obama will offer remarks in remembrance of the victims and on behalf of the survivors, Nixon's website said.