State officials said today that they still have not determined what caused a building collapse that killed three workers in Greenwood Thursday.

"The Department of Labor is putting together the totality of its resources on this alone,'' said Lori Torres, Indiana commissioner of labor, adding that her office has 12 employees assigned to the investigation.

Torres and Jeff Carter, deputy commissioner of the Indiana Occupational Health and Safety Administration, spoke at an afternoon news conference at the construction site today.

Carter said investigators are still trying to determine whether the Dayton Freight construction site was properly braced during heavy rain and winds that swept through northern Johnson County about 4 p.m. Thursday.

State building codes require that fresh masonry such as that used in the Dayton Freight building have some kind of bracing, Carter said.

Department officials said they still have not determined whether the construction site was braced appropriately.

In addition, Carter said the victims were employed by a masonry company that has been linked to extensive safety violations.

The men worked for Division 4 Masonry of Brownsburg.

Carter said Division 4 operates from the same address previously listed for Cornerstone Masonry, a company which "has an extensive list of violations dating back to 1996.

"Eighty-five percent were classified as serious violations.''

Many of the violations involved use of scaffolding, officials said.

"We're still trying to ascertain the relationship between Cornerstone and Division 4.'' Carter said.

"They share an address and the last names of the principals are the same.''