The Coast Guard is searching for a missing crewmember from a tugboat that sank in the Mississippi River.

Coast Guard officials say the UTV Miss Natalie capsized and sank near mile marker 163 on the lower Mississippi River near Baton Rouge about 8 a.m. Saturday.

The Coast Guard says five people were aboard the tug. Four people were rescued.

A search is being conducted by a helicopter from Coast Guard Air Station New Orleans, divers from the Port of South Louisiana, and a side scan sonar team.

River traffic is restricted from mile marker 158 to mile marker 162 to allow rescue crews to conduct their search safely.

No names have been released.