Uber Technologies, Inc. suspended its self-driving cars program in Tempe, Arizona following a high impact collision with another vehicle.

The company suspended autonomous vehicles testing in Arizona and Pittsburgh after one of its self-driving cars crashed into another vehicle and flipped.

The company took action after someone uploaded photos to Twitter.com showing a Volvo flipped over on its side, according to Bloomberg.com.

Officer Josie Montenegro of the Tempe police department said the Uber was not at fault in the accident. Another driver failed to yield the right of way.

“There was a person behind the wheel,” Montenegro told Bloomberg News, referring to the driverless car. “It is uncertain at this time if they were controlling the vehicle at the time of the collision.”

Company officials confirmed one of their drivers was behind the wheel of the Volvo when another car failed to yield and broadsided it. Uber didn’t say if their employee was operating the vehicle at the time or if the employee suffered any serious injuries.

An Uber spokeswoman said “we are continuing to look into this incident and can confirm we had no backseat passengers in the vehicle.”

Previous incidents involving driverless cars tested by Google and Tesla resulted in injuries and tens of thousands of dollars worth of damage.