State Transport Police determined Monday that half of the trailer brakes were not functioning on a flatbed rig that crashed into a Charleston police car and sent two officers to the hospital, Charleston Police Lt. Jason Emanuele said.

The trucker rounded the curve in the long, tall ramp that connects Interstate 26 eastbound and the Arthur Ravenel Jr. Bridge traveling at an estimated 80 miles per hour, Emanuele said.

The trucker had a beginners permit and was driving with a fully-licensed commercial driver as his partner as required by law.

After being closed for about five hours because of an accident, the ramp that connects Interstate 26 eastbound and the Ravenel Bridge re-opened at about 3 p.m., Charleston police said.

Two Charleston police officers were injured Monday morning when their cruiser was hit by the 18-wheeler, police spokesman Charles Francis said.

The tractor-trailer hit the parked police cruiser at about 9:30 a.m., Francis said.

Both officers were treated at Medical University Hospital and released, Francis said.

The two officers were on the ramp, along with some Charleston firefighters and a State Highway Emergency Program worker. They were all assisting the driver of a disabled propane truck, he said.

The 18-wheeler sideswiped a car, rear-ended the SHEP truck and then broadsided the cruiser while the officers were inside of it, Francis said.

The fire department immediately removed one of the officers from the vehicle, but the other officer had to be extracted with rescue tools, Francis said.

The driver and passenger of the tractor-trailer were taken to a hospital to be checked out.

The S.C. Highway Patrol and Transport Police are investigating the wreck.

One of the officers, who was trapped in the cruiser, gave a thumbs-up sign after being freed by rescue workers, he Francis said.

The accident occurred just past the curve on the ramp that connects Interstate 26ís eastbound lanes and the Ravenel Bridge.

The rear of the cruiser was crushed by the impact. The semi-truck was pulling a flatbed trailer.

Northbound traffic from I-26 to Mt. Pleasant was blocked. Officials were working to re-open the ramp.