Washington state has cleared one of five companies being investigated for a construction accident that killed four people.
The state Department of Labor and Industries said Monday it has closed its investigation into Seaburg Construction without finding any violations, The Seattle Times reports.
A tower crane collapsed in late April at the South Lake Union construction project in Seattle and struck six vehicles. Two ironworkers who were in the crane and two people in cars died.
Some experts say the collapse resulted from premature removal of bolts fastening sections together.
Officials say Seaburg provided crane operators, but was not involved in dismantling the crane when it collapsed.
The state is continuing its investigation into GLY Construction, Northwest Tower Crane Service, Omega Morgan, and Morrow Equipment.