TULSA, Oklahoma - Tulsa Public Schools is wrapping up a few big projects, but they're not done yet. With summer break about to end, the district is rushing to finish up work on school buildings.

Imagine trying to spend $7 million in a summer, Tulsa Public Schools is doing that, with a massive renovation that's still underway with just a few weeks to go before school.

There's hardly a spot at Central High school left untouched after a summer of constant construction. The hallways are filled with pipes and pieces of just about every system in the building.

“It's just rush, rush, rush, and you can have it almost done, but not have the heat done, you don't really need that in August,” said Bob LaBass with Tulsa Public Schools.

The project at Central is the biggest one of the summer, and the last one from a $354 million bond issue.

At Central, the building is getting fire sprinklers for the first time; it was built before they were required, the lights are being replaced with LED's that use less than half as much electricity, but the biggest job was replacing boilers and chillers with modern equipment.

The old system had one setting for the entire building. The new one can be controlled room by room.

“They've done the hardest part and now it's just putting it back together," LaBass said.

At Lindbergh Elementary a new library is almost done; it's the first storm shelter with windows the district has ever built.

It's a library with enough space to hold all the students, the main entrance can be blocked with a thick steel garage door, the roof is reinforced concrete and the windows are heavy and thick bulletproof glass that can stand up to a tornado.

“It's a concrete bunker, basically. Any opening is going to have this kind of glass in it,” said LaBass.

They're down to the details now, and another library shelter at Mitchell elementary is about a month behind it.

Once it’s wrapped up, the next big projects will focus on creating room for students, especially in East Tulsa elementary schools.

Tulsa still has 143 portable buildings being used for classrooms at overcrowded schools, so they'd like to expand schools where they can to create permanent space.