sergeant tnchs is no longer on dutiy and was transferred to a desk job at headquarters, while an internal affairs investigation is underway. >> if it plays out the way it certainly looks it's going to, the discipline will be swift and severe. >> reporter: what might that be. >> it will be a very stiff suspension, to be sure. did. >> reporter: but sergeant "t" appears to be backing away from his facebook post, sell telling sf weekly, quote, there was no drunkenness, no, no, god no. that was done tongue in cheek. and the officer said, he was a passenger, not the driver. the mayor believes whatever was going on was irresponsible. >> to the extent that the video has anybody -- whether it's an officer or somebody promoting or being proud of going 100 miles per hour in the broadway tunnel is absolutely dangerous. and people should be held accountable. >> reporter: that tunnel, which runs from larkin street in russian hill to powell in busy chinatown has a posted speed limit of 35 miles per hour. it took our news crew 40 seconds to get through. we timed sergeant "t"'s video and it appears to tak