(Image source from: kptv.com)

One person was identified unaccounted after a drilling rig, toppled onto its side near Sky Harbor Airport Monday.

Capt. Jake Van Hook, an official of Phoenix fire department said that, "It is believed that he was the operator of the device”.

Because of the insecure situation, he did not know how long it would take firefighters to safely get that person on to protection.

Van hook stated in a mail to press and media outlets that "We do not have any information on the individual or his condition at this point," he also said that, "Due to the equipment being on [its] side and the instability of the trench being worked on, it will take firefighters considerable time to determine if this will be a rescue or recovery."

The Phoenix Fire Department officials have not yet released the name or condition of the employee involved in construction.

The drilling rig had fell over at about 9:30 Monday morning "as the construction being done was for the Sky Train guideway system," according to reports of Van Hook.

Operations are working out at Phoenix Sky Harbor International Airport that is not affected by the work, Phoenix Fire Department is making efforts at the scene of the accident.

Authorities say that the trench where the rig toppled is unstable and that made situation complicated.

“In this situation, you’ve got the loose dirt. You have the unnatural position of this drilling rig," said Van Hook.

Heavy machinery like the rig that fell over can be used to drill wells, sample mineral deposits, rock, soil and groundwater, and install things like underground utilities or tunnels.

“We have this large piece of equipment over a hole that we don’t know how certain the depth or stability of that soil is around the equipment," said Van Hook.

Phoenix Fire technical rescue teams are at the scene to monitor the safety of the operation and assist in making the connections necessary to move the drilling rig.

By Lokesh