The shooting unfolded when 50 people gathered for a celebration of life near North Market Loop in Baytown, about 25 miles west of Houston.
It erupted at around 6.40pm on Sunday local time, just as people at the vigil had released balloons into the air.
Harris County Sheriff Ed Gonzalez said: “Right as they were releasing the balloons up into the air was when the vehicle came. Almost at that exact time is when they opened fire into a crowd.”
Disha Allen, a woman in her 20s, was later pronounced dead after being taken to hospital.
Of the 14 injured, three were in critical condition, Mr Gonzalez said. A young child was believed to be among those injured. Three of the wounded were taken to hospital by helicopter.
Officers were later called to the medical center in Baytown where some of the wounded were taken because a “disturbance” erupted there, Mr Gonzalez said.
Authorities did not immediately provide a description of the suspect. No arrests have been announced.
Witness Sidney William told ABC13 he heard approximately 20 to 30 gunshots, which led to people “screaming and running to their cars”.
When asked if he believed the attack was “targeted and not random”, he said: “Sounds about right.”
The motive of the shooting is not yet known. The vigil was being held for a recent homicide victim from the Baytown area.
The suspect is believed to have been driving a small, dark-coloured saloon.
