AUSTIN (KXAN) — The family involved in a deadly car crash in which two young siblings were killed in late April is suing a North Austin bar that allegedly served the suspected drunk driver that caused the collision, according to a lawsuit filed last week.

The lawsuit alleges sports bar Cover 2 was negligent when it allowed John Alvarado-the suspected drunk driver in the accident-to consume alcohol until he was intoxicated and let Alvarado leave while intoxicated, among other claims, according to the lawsuit. The bar is located on U.S. Highway 183 less than a mile north of Anderson Mill Road.

Kirsten (left) and Koby Draper were killed in a crash along US 183 near Liberty Hill.

Robby and Crystal Draper are listed as the plaintiffs in the lawsuit. They are the parents of Kirsten, 10, and Koby, 15, who died April 22 at the scene of the crash near Liberty Hill, according to authorities. The Drapers are seeking damages in excess of $1 million, court documents state.

Crystal, who was driving the children, and two of her sons were also seriously injured when Alvarado slammed into the back of their vehicle near 183 and Saratoga Springs Road, according to police.

Dallas-based attorney Michael Grossman is representing the Drapers in the lawsuit. Grossman described the case as a “tragedy.”

“The damage that this bar has, in essence, inflicted on this family is immeasurable,” Grossman said. “No amount of money would bring justice to this family.”

KXAN reached out to Cover 2 and the attorney representing the sports bar, but we haven’t heard back from them yet. We will update the story, if the bar or its attorney respond.

Cover 2 filed an answer the Draper’s lawsuit. In it, the bar denies any wrongdoing. The bar states the allegations and claims against it are invalid and should be stricken, according to court documents.

KXAN checked with the Texas Alcohol and Beverage Commission, and the sports bar doesn’t have prior violations.

Alvarado has been charged in Williamson County with two counts of murder and three counts of aggravated assault with a deadly weapon. He has previously been arrested twice for driving while intoxicated, court records show.

The Drapers have separately sued car manufacturer Nissan, alleging the family’s Altima had “inadequate occupant protection systems.” The lawsuit alleges gross negligence and wrongful death against the carmaker, according to court documents.