A WTMJ-TV photographer who witnessed the crash says the semi jumped the median on Interstate 94 about 11 a.m. The Milwaukee Journal-Sentinel reported that the accident happened near Mount Pleasant, about 24 miles (38 kilometers) south of Milwaukee.
Photos from the scene indicate the semi plummeted off the edge of the interstate onto a road beneath. Near-black smoke washed across the interstate from the still-burning truck. Racine County Medical Examiner Michael Payne said two people were killed, and the sheriff reported several injuries but hasn't provided details.
Authorities closed all lanes of the interstate and transportation officials estimated it would be hours before the scene could be cleared. A Flight for Life helicopter was called to the scene, but was unable to fly because of adverse weather, Tammy Chatman, a spokeswoman for the service told the Journal Sentinel. There had been scattered rain showers throughout southeastern Wisconsin most of Wednesday morning.
Chatman said Flight for Life is sending one of its ground units to help instead. Authorities have not yet said what caused to the crash.