Teams searched for hazardous materials Friday in a neighborhood damaged by a massive chemical plant explosion, as investigators prepared to look into what caused the blast.

Meanwhile, residents waited to see if they would be allowed to permanently return to their houses for the first time since Wednesday's blast, which left a massive pile of rubble and woke people sleeping miles away.

"I just want to see what the damage is and get back to normal. A good night's sleep would be good," said Susan Tropeano, 45, who fled her house with her husband and 16-year-old son after the explosion.

About 10 homes were destroyed and another 60 were damaged when the blast obliterated the former CAI Inc. chemical plant. No serious injuries were reported.

Governor-elect Deval Patrick visited the site Friday, meeting with safety and local officials.

State Fire Marshal Steve Coan said the hazardous materials teams were making sure investigators could safely begin their lengthy probe.

"It will take quite some time to just get in and document the scene," Coan said. "It's nothing more than a pile of rubble."

Fire Chief James Tutko said about dozen of the damaged homes will require some reconstruction. The other 50 were being evaluated, and residents could likely return to those in "a matter of days, not weeks," he said.