MUSKOGEE, Oklahoma - Weather is being blamed for a four-vehicle crash involving a semi just outside of Muskogee early Tuesday.  Four people were taken to the hospital after the 4:38 a.m. crash on Highway 16 at 74th Street, according to the Oklahoma Highway Patrol.

OHP said Elma Lang from Boynton is in critical condition, and another person was also admitted to the hospital. Lang, 58, was freed from his truck by Mountain View Fire Department.

Steven Clark, a 53-year-old Muskogee resident, was taken to a Tulsa hospital where he's said to be stable. Two other people were treated and released for their injuries.

Troopers said the semi was turning onto Highway 16 when four vehicles - two on each side - crashed into its trailer. Driver Clyde Savage wasn't hurt. The 49-year-old man is from Horton, Alabama, OHP said.

The wreck shut down traffic on the highway for a few hours. Troopers interviewed witnesses throughout the morning to learn more about the crash.

They said the fog was especially heavy, and drivers could only see about 50 feet ahead of them.

"With that visibility, you don't know what's in front of you," said Trooper Randy Cox. "In this case, it happened to be a semi blocking the whole, complete highway."

The wreck remains under investigation though troopers know weather contributed to the cause.