BREAKINGWorker missing after drill rig topples over at Sky Harbor AirportOfficials continue to search May 23, 2018, for a missing drill-rig worker who is believed dead after a collapse Monday morning.Phoenix Fire DepartmentOfficials continue to search May 23, 2018, for a missing drill-rig worker who is believed dead after a collapse Monday morning.Phoenix Fire DepartmentCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The Arizona RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/TheRepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Nick Oza/The RepublicInvestigators look down at a toppled drill rig that was being used in the construction of the Sky Train guideway system at Sky Harbor International Airport Monday, May 21, 2018, in Phoenix. The Phoenix fire department said one person is unaccounted for and their condition is unknown at this time due to the rig being on its side.Matt York/APInvestigators look down at a toppled drill rig that was being used in the construction of the Sky Train guideway system at Sky Harbor International Airport Monday, May 21, 2018, in Phoenix. The Phoenix fire department said one person is unaccounted for and their condition is unknown at this time due to the rig being on its side.Matt York/APA plane takes off above a toppled drill rig that was being used in the construction of the Sky Train guideway system at Sky Harbor International Airport Monday, May 21, 2018, in Phoenix. The Phoenix fire department said one person is unaccounted for and their condition is unknown at this time due to the rig being on its side.Matt York/APConstruction workers and airport personnel stand near a toppled drill rig that was being used in the construction of the Sky Train guideway system at Sky Harbor International Airport Monday, May 21, 2018, in Phoenix. The Phoenix fire department said one person is unaccounted for and their condition is unknown at this time due to the rig being on its side.Matt York/APA toppled drill rig that was being used in the construction of the Sky Train guideway system lies it's side at Sky Harbor International Airport Monday, May 21, 2018, in Phoenix. The Phoenix fire department said one person is unaccounted for and their condition is unknown at this time due to the rig being on its side.Matt York/APPhoenix Fire Department rescue crews were at the scene of a toppled drilling rig at Sky Harbor Airport May 18, 2018. One man was believed to be trapped in a hole.Nathan J. Fish/The RepublicCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Phoenix Fire DepartmentCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Phoenix Fire DepartmentCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Phoenix Fire DepartmentCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Phoenix Fire DepartmentCrews attempt to clear the collapsed equipment on May 22, 2018, where a worker is believed dead following a work-site incident at Phoenix Sky Harbor International Airport the day before.Phoenix Fire Department