The service is scheduled for Thursday at Baylor University.
Last week's blast left 14 people dead and injured 200 others. The explosion was largely overshadowed by the Boston Marathon bombing.
Federal and state investigators are still trying to determine what caused the fire that set off the explosion. Authorities say there are no signs of criminal intent.
Obama was already scheduled to be in Texas this week. He'll headline a Democratic fundraiser in Dallas Wednesday night, and then attend a dedication ceremony for President George W. Bush's library.
School underway in tiny Texas town hit by blast
A tiny Texas town shaken by tragedy took a major step toward normalcy Monday as hundreds of students went back to school days after a fertilizer plant explosion leveled homes and killed at least 14 people.
In a scene recalling the first day of school, teachers and staff waited for students to shake their hands and pat them on the shoulders. Some parents took the day off to walk or drive their children there. Classmates who hadn't seen each other since Wednesday talked and laughed -- with dozens of reporters and TV cameras chronicling their arrival.
Most of the students were headed to new classrooms because the old ones were severely damaged by Wednesday's explosion at West Fertilizer Co.; the schools weren't in session that evening. Intermediate students were sent to the local elementary school, which set up trailers for classrooms in back. Middle- and high-school students were bused from a car dealership parking lot to nearby Waco, where officials had quickly made space for them.
"I'm just glad to get back to our routine," said 14-year-old Sofia Guerra, sitting in the car Monday morning with her mother, Erika, as they dropped her sister off at West Elementary School.
"It's unknown," she added. "We don't know what to expect."
Counselors will be in each classroom and available separately for students still dealing with the emotions of the blast. In the town of about 2,700 people, almost everyone knew someone killed, hurt or displaced. Some teachers who reported to work Monday had not been home since the blast, said Jan Hungate, assistant superintendent at West Elementary.
West and Connally are rivals -- or were until Wednesday night. On Friday, Connally staff and volunteers began turning the vacant intermediate school into a high school, painting the classrooms in West's black-and-red school colors and scrubbing the floors.
Wesley Holt, a Connally district spokesman, said they also placed binders, notebooks and pens on each desk. Other districts donated furniture, and a food-service company prepared the cafeteria, he said.
"We honestly had to ask people to stop sending school supplies," Hungate said.
Debbie Ratcliffe, a spokeswoman for the Texas Education Agency, said state officials have offered to waive end-of-year tests and other requirements as needed. Hungate said the district was considering several options on testing.
Nickole Hayes dropped her three daughters at the dealership Monday. Her family was inside their home about 200 yards from the explosion site. The impact blew holes in her ceiling, knocked off doors and blasted the windows, she said.
The family had to live separately for a few days until a doctor from nearby Hillsboro donated his second home for them to stay in, she said.
She said her daughters felt doubly displaced, first from their home and now from their school.
"They're aggravated. They're disappointed," Hayes said. "They know they have to go back, but there's not a good way to be uprooted again."
Chad Rizo, father of 7-year-old Hunter, took the day off to walk his son to school. Rizo said his mother-in-law and several friends lost their homes and belongings.
While his son was excited to go to school with older friends, Rizo said the outside media attention would need to subside before things could return to normal.
"When West is left to clean up, that's going to hit home for a lot of people, I think," he said.
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