When tech companies show up in a disaster zone, it’s not pure altruism.

“The reason why companies will come in after disasters is that the slate has been swept clean,” said Robert Collins, a professor of public policy at Dillard University in New Orleans. “There’s a void. There’s a vacuum.”

That means less red tape and possibly big paydays for solutions. Google parent company Alphabet is already making moves. The Federal Communications Commission approved its license to launch huge helium balloons over Puerto Rico to try to provide emergency cell service. Tesla CEO Elon Musk has pledged hundreds of energy-storing batteries to the island, and offered to rebuild its power grid using solar technology.

Collins said Puerto Rico’s long-term economic problems mean it may be inclined to give corporations free reign.  

“When that happens, you’re going to see health and safety regulations tossed aside,” Collins said. “And there’s no guarantee that the locals are going to get most of those jobs.”

Local knowledge is too often thrown aside in rebuilding, said Jarrod Goentzel at MIT’s Humanitarian Response Lab. He said Puerto Rican leaders need to vet who’s offering innovation — versus experimentation.

“It’s not a time to experiment with something that hasn’t been proven,” Goentzel said. “But rather leverage ones that have been proven to some extent but might not have been used in this particular way. And that’s innovation.”

Alphabet used its helium balloons after recent flooding in Peru. Tesla has built solar grids on other islands. Madhu Beriwal with Innovative Emergency Management, said companies should not over-promise.

“You create a sense of hope, especially when they hear names like Alphabet and Elon Musk that our troubles are going to be over soon,” Beriwal said. “And if that doesn’t bare out, survivors are affected even more by having their hopes dashed.”

Puerto Rico’s needs are great — with more than 80 percent of the island still without power, and 75 percent of cell towers down.