In the meantime, trains are being rerouted through Birmingham.

The city school system does not yet have an estimate for one middle and two elementary schools with severe damage, said spokeswoman Lesley Bruinton. Their 1,000 students were re-assigned to other schools.

Tuscaloosa County Schools had slight damage to five schools but a sixth was heavily damaged, so students were moved to an unused building, said Patrick Conner, chief financial officer.

In addition to repair and rebuilding costs, the system is seeking Federal Emergency Management Agency funds to add shelters to nine schools, he said. These shelters are hardened areas with reinforced poured-concrete walls, separate HVAC systems and generators. The structures can double as interior hallways, multipurpose rooms, cafeterias or libraries, Conner says.

A shelter is needed for wood-frame structures in tornado areas, said Dr. Andy Graettinger, associate professor of civil, construction and environmental engineering at the University of Alabama.

He’s part of the team that studied tornado wind-force levels and structural damage locally and in Joplin, Mo., in an effort to develop engineering and design changes for safer buildings.

“We quickly saw, in the center of the storm, at EF3 and EF4 [that] … you need a safe room,” he said, referring to a reinforced- concrete structure that can be built into a house or garage or as a separate structure.

Buildings at the edge of the storm better withstand high winds if they are built with hurricane clips at the roof and hurricane straps at the foundation, said Graettinger, who also studied damage from Hurricane Katrina.