OAKLAND, Calif. -- A United Parcel Service big rig hurled 30 feet off an Oakland freeway overpass early Thursday, slamming onto the roadway below, injuring the driver and leaving stunned witnesses nearly speechless.

The California Highway Patrol said the incident took place at around 2 a.m. on the Jackson Street overpass on 880 in downtown Oakland.

The 51-year-old driver of the 2003 Toyota was speeding south on Highway 880 just north of Oak Street when he made an unsafe lane change, the CHP reported. The Toyota swerved into the No. 3 lane and struck a UPS truck driven by a 47-year-old man.

The big rig driver then lost control of his vehicle, crashing into the concrete guardrail, ripping away large chunks of cement. The big rig hurled over the overpass, flying some 50 feet in the air before landing on the roadway 30 feet below.

“You could hear him start screeching his brakes,” Lamar Moore, who was on Jackson Street and witnessed the plunge, told KTVU. “I heard one thump, two thumps and then he started coming down. He flew between the tree branches. He is very lucky (not to have been killed.)”

Battalion Chief Baron White said the location where the truck landed aided in the rescue of the driver.

“The crews were very fortunate that the location the vehicle came to rest was between two trees so it was fairly stable,” White told KTVU. “We could focus our attention on the patient removal…Our crews did an excellent job removing the patient rapidly.”

The truck driver was taken to a local hospital, his condition was not immediately known.

The driver of a Toyota that clipped the side of a UPS truck was arrested for driving under the influence, according to the CHP.

Caltrans crews spent several hours cleaning up the accident scene and rush hour traffic on the busy 880 commute corridor was not impacted.