MONROE — Four people were taken to the hospital Monday night after a cottonwood fell over U.S. 2, resulting in a series of crashes just east of Monroe.

The accidents were reported around 11:30 p.m. and involved a truck, two cars and a motorcycle.

The tree blocked the eastbound and westbound lanes, according to the Washington State Patrol.

No heavy winds were noted beforehand.

U.S. 2 is closely watched for safety issues after decades of fatal and serious injury accidents led to road improvements, but trees falling over the highway in the summer has not been a major concern.

“It’s pretty rare,” State Patrol Sgt. Mark Francis said. “I don’t think it’s a problem with Highway 2.”

A 62-year-old truck driver from Eastern Washington escaped injury when his westbound rig was hit by the large cottonwood. A car driven by a Sultan man, 70, struck the truck. The Sultan man was one of the four people taken to Evergreen Health Monroe for treatment.

A Steilacoom motorcyclist, 22, and a 58-year-old Duvall woman driving in a Nissan were headed eastbound. Both struck the tree over the roadway. They and a passenger in the Nissan were taken to the Monroe hospital.

Maintenance crews with the state Department of Transportation used a chainsaw to remove the tree. The highway was cleared by 2:30 a.m.

The tree snapped off around 25 feet up, said Harmony Weinberg, an agency spokeswoman.

Crews examined the cottonwood and it appeared to be healthy, she said.

Road workers routinely monitor the condition of trees along the highway.

“This wasn’t a tree that popped up on anybody’s radar,” she said.

There is good reason to keep a close eye on trees along that stretch of highway.

In 2012, a Ponderosa pine, roughly 125 feet tall and four-feet wide, toppled onto a SUV, killing a Bothell area couple east of Stevens Pass. Other family members survived the crash. A $10 million settlement was reached with the state two years later.

More than 38 trees fell after heavy snow in 2012 turned to ice on their branches. Alders snapped and Douglas fir were uprooted. That triggered a four-day closure of the major east-west highway. Each tree that fell was more than a foot in diameter.

Eric Stevick: 425-339-3446; stevick@heraldnet.com