TAMPA, Fla. (WFLA) — A medical helicopter is responding to a crash involving a semi-truck in Polk County.

The crash happened at about 5:15 a.m. on U.S. Highway 27 and Scenic Highway South.

Authorities said it appeared a SUV may have rear-ended the semi, but there is no word on what led to the crash or how many people were injured.

Authorities said a medical helicopter was on its way to the scene.

This story is developing and will be updated.