The damage appears to much worse than initially thought, as a result of the USS Port Royal, an American cruiser, running aground on February 5th. The ship was returning to its base in Hawaii after the first day of sea trials. The ship slid into a shoal of sand and rock, which was actually construction debris from a nearby air port. The Port Royal had spent the last four months in a shipyard, getting a normal batch of upgrades and maintenance. The 9,600 ton ship has been in service for 15 years, and is the 27th, and last, Ticonderoga class cruiser to be built.
It took four days to get the cruiser off the shoal, which was done by removing about a thousand tons of weight from the ship. It's not been announced how it hit the shoal, which is marked on charts. The Port Royal draws 33 feet of water, and the shoal is 22 feet under water. The captain of the Port Royal was relieved, which is normal for a grounding such as this.
Initially, he only damage mentioned was to the propellers (the tips were torn off), and a leak in one of the sonar domes. There was no hull breach. But even then, it was believed that the propeller shaft and shaft bearings would have to be replaced as well.
The actual damage turned out to be far worse. The drive shafts and the steel supporting them were twisted out of alignment as the ship was rocked back and forth. It's feared that this damage might be so bad that the drive shafts, reduction gears and engines might have to be replaced. This could cost tens of millions of dollars.
The sonar dome has to be replaced, and the hatches for some of the missile cells (silos) were also twisted out of alignment and have to be replaced. Some of the sensors and antennae on the main mast were twisted out of alignment by the shock of hitting the reef, and have to be repaired or replaced. Instruments and sensors on the bottom of the ship were destroyed or damaged by the grounding. The water exhaust and intake ports in the hull were jammed with debris, and have to be repaired or replaced (otherwise the sanitation, air conditioning and ballast systems will not work)
So after one day of sea trials, the Port Royal is right back to the shipyard and dry dock. The ship may be there for months, and the total cost for repairs may be over $50 million. There will probably be courts martial for whoever screwed up the navigation that put the ship on a known shoal. Professional mariners don't do that sort of thing in clear weather and calm seas.