Fire crews said the Tacos to Go restaurant on Highway 70 went up in flames around 11:30 p.m. Sunday.
As firefighters tried to put out the hot spots at that fire, they noticed another fire down the road. Absolute Wireless, which opened three weeks ago, was destroyed by the fire. The owners said they did not have insurance yet.
"The ink wasn't even dry on the leases to be finalized and hadn't even gotten a certificate of insurance," said Kenneth Michel.
Another business, Platinum Hair Gallery, had a lot of smoke and water damage.
"One of my wife's clients called and said the building was on fire," said owner Chris Hart, who heard about the fire as he drove home from a Super Bowl party.
An SBI arson dog was brought in to search the buildings to see if an accelerant may have been used to start the fires. Clayton police hope to have a cause by Tuesday.
Officials said Tacos to Go recently reopened after an electrical fire damaged the store three months ago.