Elon Musk Fires Back at San Francisco as City Launches Investigation Into Modification He Made at Twitter HQ

CHICAGO, IL - JUNE 14: Chicago Engineer and tech entrepreneur Elon Musk of The Boring Company talks about constructing a high speed transit tunnel at Block 37 during a news conference on June 14, 2018 in Chicago, Illinois. Musk said he could create a 16-passenger vehicle to operate on a high-speed rail system that could get travelers to and from downtown Chicago and O'hare International Airport under twenty minutes, at speeds of over 100 miles per hour. (Joshua Lott/Getty Images)