NTSB Chairman Robert Sumwalt said "As the aircraft was climbing through about 32,500 feet, the engine parameters, both RPM indicators on the left engine went down to zero, oil pressure went down to zero, and the engine vibration increased significantly on the left engine," he said.
Shortly thereafter, the cabin altitude warning horn was activated, indicating that the cabin altitude was "going down to about 14,000 feet," said Sumwalt. The aircraft then began an uncommanded left roll at about 41 degrees of bank angle, compared to the normal 20 to 25 degrees of bank that is typical when flying a commercial airliner, such as the 737, according to Sumwalt.
41 deg bank and roll to left is pretty significant, that probably when the debris hit the passenger window, as mentioned above there was a delay when the window was hit after the failure.