in manhattan, kendis, i know you were there when there was still natural light outside -- >> reporter: whoa! >> oh, did it just happen? the lights just came on behind you! let's go back to kendis. look at that! that looks like that was the final grid they were working to restore. kendis, is the marquee lit up? >> reporter: it is back on! the marquee's back on. >> msnbc's chris pollone is live in new york city. kendis was excited. we're all glad the power's back on, but what really caused this? >> reporter: yeah, that was a crazy few hours. that was a great moment there. and that's the question, jo lyng, that city and state leaders are asking themselves this morning, exactly why did this happen? the local power company over manhattan, over new york city, con edison, initially blamed this on an equipment failure, but a full investigation is under way this morning to figure out exactly why that equipment failed, plunging a great swath of the west side of manhattan into darkness.