Road construction

Joe Bushnell

The Washington State Department of Transportation has now figured out what caused construction lumber to fall off the Highway 16 Nalley Valley Viaduct project and smash onto South Tacoma Way on June 29th.

As KPLU reported, the falling lumber barely missed landing on a man on a moped.

WSDOT says the contractor has now determined that the cause was a defective four-by-six wood support beam, which collapsed spilling the construction lumber onto the roadway below.

Joe Bushnell

The Washington state Department of Transportation is trying to figure out what went wrong on Saturday when dozens of pieces of construction lumber on the Nalley Valley viaduct project on Highway 16 came loose and fell onto the roadway below, smashing into pieces as drivers watched in disbelief.