SEATTLE -- The state Department of Labor and Industries has shut down three construction cranes in Seattle and Renton because of "potential safety problems."

Two cranes in downtown Seattle had modifications that "did not meet structural integrity assurances," L&I said in a news release issued Thursday morning. They have portions from different manufacturers.

Also, the electrical systems of those two cranes and one in Renton had not been evaluated and approved, L&I said.

"The safety of workers and the public is of utmost importance, and that's why we have shut down these cranes until they meet basic code requirements," said Steve Cant, assistant director for L&I’s Division of Occupational Safety and Health, in the news release.

L&I said it has open investigations with crane distributor Lewis Equipment Company of Texas and the general contractors using the cranes: Lease Crutcher Lewis, Turner Construction and Lydig Construction.

In a press release from Lydig Construction Inc., they said the problem with their crane is not with "structural integrity concerns," but with their "electrical certification." Lydig Construction Inc. said they are working with L&I to resolve the concerns, and that they have mobilized another crane to continue progress on the project.

The cranes are at construction sites located at Fifth Avenue and Yesler Way in Seattle, 1823 Terry Avenue in Seattle and at 400 South 43rd Street in Renton.

Associated General Contractors spokesman Jerry VanderWood said, "AGC and the affected contractors are working collaboratively with the Department of Labor and Industries to resolve the situation. AGC and its contractor members take safety seriously."

The department said the cranes will be evaluated and certified before they can return to work.

The cranes are made by the Sun Cranes company are the only such cranes erected in Washington.

L&I said its action is not related to the collapse of a crane last week in New York.

Two workers died and one was hurt when the top section of a crane broke off and smashed into an apartment building on Friday.

In November 2006, Microsoft attorney Matt Ammon was killed in Bellevue when a crane collapsed and crashed into his condo.

SLIDESHOW: Nov. '06: Bellevue Crane Collapses