"There was no one single cause for this tragedy," said Capt. Charles LeBlanc, commander of the Patrol's Criminal Investigation Division. "There was a combination of circumstances that led to a horrific end."
O'Connell was helping monitor traffic along a detour set up in the wake of the collapse of the Skagit River bridge when his motorcycle collided with a box truck.
After monitoring the length of a traffic backup, the trooper was returning to where another trooper was directing traffic. He was moving up the shoulder, outside the fog line, passing to the right of the box truck.
Investigators say the box truck driver did not see O'Connell's motorcycle prior to initiating his turn and speed was not a factor in the collision.
"The reason we have motorcycles is precisely because they can maneuver around traffic," LeBlanc said. "Passing on the right is something our troopers are trained to do in the performance of their duties, and like many of our duties, it involves risks."
LeBlanc said another complicating factor was the presence of a guard rail that cut off O'Connell's avenue of potential escape. Perhaps most tragically, after striking the box truck O'Connell fell underneath it, LeBlanc said.
"A couple of seconds in time, or a couple of feet either way, and we'd likely have had a very different outcome," LeBlanc said.
LeBlanc said that O'Connell was not using his emergency lights and siren at the time of the collision, in keeping with agency training. He said experience has shown that some drivers, upon hearing a siren, make sudden maneuvers to the right. If troopers are forced to pass on the right, they generally turn off their emergency lights and sirens to avoid being hit.
LeBlanc said the truck driver agreed to a voluntary blood test for alcohol or drugs, and there is no evidence he was impaired in any way. He added the driver cooperated fully in the investigation, no citations have been issued, and no charges are being sought.
O'Connell is the 28th Washington State Patrol Trooper to be killed in the line of duty. The new Skagit River Bridge has since been renamed the Trooper Sean M. O'Connell Jr. Memorial Bridge in his honor.