A rollover on the South Side killed four people and San Antonio police believe drinking may have led to the deadly crash.
SAPD officers and paramedics responded to the crash just after 2 a.m. Monday on the entrance ramp from Interstate 35 North to Interstate 10 East.
Investigators said they believe the driver was headed northbound and lost control of his Chevrolet Trailblazer.
"Each of the individuals involved in that crash were thrown from the vehicle onto the highway, so it appears that none of them were wearing seatbelts," said San Antonio police Chief William McManus.
All four victims -- two men and two women -- were pronounced dead at the scene. Investigators said no one inside the SUV was wearing seat belts at the time of the crash.
SAPD investigators said there was a strong smell of alcohol in the SUV, but the crash was under investigation.
"The driver of the vehicle did have a bottle top of an alcoholic beverage in his hand," McManus said.
He said the wreck was proof that despite efforts to curb drunken driving, it is still happening far too often.
"DWI -- I mean, we talk about that all the time, and, again, I think it's a matter of people thinking, 'It's not going to happen to me,'" McManus said.
The names of the victims have not been released.