I have been using an OWC Mercury Elite -AL Pro 1.5TB external hard drive with my Macbook Pro (2011, 2.3GHz, intel core i7, osx 10.6.8). Tonight while I was using it, I accidentally bumped my computer which caused a cable to come loose and disconnect the drive without being properly ejected. After that, I wasn't able to mount the drive. I attempted to validate the drive using Disk Utility and got the error "invalid node structure". Attempted to repair it using disk utility, but it wasn't able to. The lights on the drive are still both blue which according to the manual indicates normal functioning. It says that if the drive has failed, one or both lights will be red. I connected the drive with various cables (FW800, eSata, usb2.0) and it made no difference - disk utility was still unable to repair it. From my research online it seems like I may need to either use Disk Warrior in an attempt to repair the drive and/or DataRescue 3 to try to recover files if Disk Warrior is unsuccessful. Before I spend money on either of these programs, I just want to make sure this is the proper strategy. Any input would be appreciated. Thanks.