A preliminary Florida Highway Patrol report shows the victims, driver Maritza Vasquez and passenger Yezenia Morales, were in a 1996 Infiniti that turned into the path of a northbound dump truck on Boggy Creek Road at 10:10 a.m.
The women, both 38, died on scene.
The crash was south of State Road 417 on Boggy Creek Road, which remains closed near New Hope Road.
Infiniti was stopped at stop sign facing west on New Hope Road before the crash.
The vehicle attempted to make a left turn to travel south on Boggy Creek Road and drove into the path of the dump truck driven by Victor Gonzalez, 52, of Altamonte Springs, Florida Highway Patrol Sgt. Kim Montes said.
Motorists are urged to avoid the area.
Expect delays throughout the day as an investigation continues.