Nick Gordon -- Arrested for DUI Following Gnarly Car Crash

The good news: Nick Gordon walked away from a terrible car accident Thursday morning with no major injures. The bad news is ... he got arrested for DUI.

Law enforcement sources in Roswell, GA tell TMZ ... Gordon (who is married to Whitney Houston's daughter Bobbi Kristina) lost control of his BMW, hit a curb, took out a fire hydrant and flipped his car upside down. We're told it finally came to a rest after sliding around 200 feet.

When cops arrived on scene, we're told they discovered Nick was driving on a suspended license and cops felt Gordon's behavior gave them probable cause to arrest him for DUI.

We're told police did not conduct a breathalyzer test, but they are seeking a warrant for a blood test.