Crane operator schools across the country are being closed for the holiday season amid a crane operator’s accident that killed four workers in a crane landing.
The U.S. National Transportation Safety Board said the crash on Friday morning killed three crane operators, two workers and a passenger.
The crash occurred in the heart of the Great Plains region, which is home to some of the largest oil and gas fields in the United States.
The accident happened about 1:40 a.m.
ET at the Crane Operator School in Green Bay, Wisconsin.
Three people were killed and two more were injured, according to the NTSB.
The cause of the crash remains under investigation, the NTSb said.
The agency said the school was closed for 90 days.
The National Transportation Workers Union (NTWU) called on the school to reopen.
The union said the closure was not related to a crane accident but was an “unfortunate accident” in which “three people were lost and the lives of the other two lost in the crash.”
The NTWU called on Gov.
Scott Walker to reopen the school.
“The safety of our students, workers and communities is paramount to our families, and the safety of workers is paramount,” the union said in a statement.
The NTSB is conducting a probe into the crash.
The school is located in the town of Green Bay and is the first of its kind in the U.A.E. It is operated by the Great Lakes Engineering Company, which operates two other schools.
The company has a crane school in North Dakota and a smaller one in Illinois.
The NTB also said the schools were not equipped to handle large loads.
The incident is under investigation.
The United States has seen a string of accidents involving oil and natural gas rigs, including a 2014 oil rig explosion in North Charleston, South Carolina, that killed 21 people.
The blast prompted a recall of more than 30,000 of the rigs and a federal investigation.