Investigators looking into a suspicious fire that destroyed a Roosevelt Road gas station just moments after the store was burglarized are not ready to say the blaze was set intentionally, though less sinister scenarios have been ruled out.

Officially, the conflagration’s cause is “still undetermined,” according to Fire Chief Steve Glinke, because there is no solid evidence suggesting arson. However, investigators have concluded the flames that tore through the Citgo station at 7400 Roosevelt Rd. in the early morning hours of Nov. 17 were not ignited by mechanical failures such as faulty wiring. Glinke labeled the fire as “suspicious.”

“We can’t absolutely call it arson because we can’t prove arson,” Glinke said.

When fire and police crews responded to the address for a report of a structure fire earlier this month, officials quickly saw several signs that suggested the blaze had been set. Electricity and phone service had been cutoff from the building’s exterior, several large holes–presumably used to gain access to an office–had been cut through a back wall, and a safe was reported missing. The safe and a cash register drawer, both emptied of their contents, were later recovered in an alley in Chicago.

Police have said an undisclosed amount of cash was stolen in the after-hours heist.

Detectives have not made any arrests in connection with the burglary, nor is there a list of suspects. Police Chief Jim Ryan said officers are still processing evidence gathered from the burned out building and are exploring a number of possible theories.

Part of the reason investigators haven’t pinned down the fire’s cause is that the presence of gasoline inside the building wouldn’t be unusual, Glinke said. He declined to call in state K9 units to sniff out any suspicious chemical compounds often found in accelerants because customers and employees have likely tracked those elements through the building from the fuel pumps.

“It’s a little bit tricky because we can’t bring the fire marshal’s dog in because they’re going to hit on petroleum distillates or hydrocarbons,” Glinke said.

Glinke said his office will likely lean on the police department to make a case for charging any suspects with setting the fire. Investigators from both departments said the fire is almost certainly linked to the burglary.

“I would say that they most likely are connected,” Deputy Police Chief Tom Aftanas said. “It would be a one in a million chance to break into a place after it was burglarized just to set the place on fire.”

In separate but related incidents, two motorists passing by as crews worked to extinguish the flames were taken into custody by police. Both men, 28-year-old Reginald Jackson of Broadview and 30-year-old Andrew Berthiaume of Elk Grove, were charged with driving under the influence and failing to yield to emergency vehicles. According to police reports, both suspects disobeyed police officers attempting to redirect traffic along Roosevelt Road and drove over fire hoses being used to put out the blaze.