NBA's Kevin Porter Jr. Arrest, Cops Release Scary Crash Photos

It's a miracle Kevin Porter Jr. wasn't injured during a scary car wreck Sunday night ... cops just released photos from the scene, and his car was mangled.

Cops say the Cleveland Cavaliers player wrecked his Mercedes Benz at around 2 a.m. in Ohio, and when they responded to the scene ... officers claim they found a loaded handgun and what appeared to be weed inside the vehicle.

The 20-year-old NBA player was arrested for improper handling of a firearm, marijuana possession and more.

But, here's the crazy part, cops say Porter Jr. admitted to drinking earlier in the evening -- but did NOT present "clues of impairment" during a field sobriety test ... so he's not facing any DUI charges.

Unclear what caused the wreck at this point ... but one thing is clear -- Porter Jr. is extremely lucky to be alive.

Check out the damage to the windows, windshield and body of the car -- damage cops say was sustained when the vehicle rolled over.

You can see in the photos, the crash set off multiple airbags inside of the vehicle.

Porter Jr. pled not guilty to the misdemeanor charges and entered a no plea on the felony gun charge.