The parents of a late Texas A&M cheerleader filed a $1 million lawsuit against two school organizations that allegedly served their daughter alcohol at a football tailgate hours before she plummeted to her death in late November.

Brianna Aguilera, 19, was found dead at the base of a high-rise apartment complex after a harrowing 17-story fall. The Austin Police Department later suggested that she took her own life, but her grieving mother, Stephanie Rodriguez, publicly denounced their “lazy” investigation and quick conclusion.

Rodriguez and her husband, Manuel Aguilera, filed the steep lawsuit against Austin Blacks Rugby Club and the University of Texas’ Latin Economics and Business Association.

The lawsuit alleges that both organizations served their underage daughter copious amounts of alcohol at a football tailgate hours before her grisly demise.

The suit details Aguilera’s final hours before her ill-fated plunge.

She was served her first drink at the tailgate around 6 p.m. and continued partying for several hours while the defendants “continued serving all of them alcohol,” according to the complaint obtained by Fox 4.

Aguilera became “grossly intoxicated” and eventually staggered into a wooded area nearby. She lost her cellphone along the way — which was later recovered by police.

She left the tailgate around 10 p.m. and went to the apartment complex on the school’s West Campus, where she was supposed to spend the night. She plummeted to her death from that same apartment around midnight.

“We believe even more today this was not a suicide as has been suggested by police. This was either an accident or something much more sinister,” Tony Buzbee, lead attorney with the Buzbee Law Firm, who is representing Aguilera’s parents, said at a press conference.

The lawsuit accuses the two student organizations of violating the Texas Alcoholic Beverage Code provisions, which bar alcohol suppliers from serving minors or visibly intoxicated people.

Buzbee asserted that his team will subpoena “individuals and documents and video and data” so that they can “get to the bottom once and for all of what happened that night.”

“If the police department will not do its job, then we will do it for them,” Buzbee said.

Police claimed that they found a deleted “suicide note” on Aguilera’s phone, which Buzbee insisted was a drafted essay.

The county’s medical examiner has not determined a cause of death, and police assured that the investigation remains open.

The Post reached out to the Austin Blacks Rugby Club and the UT Latin Economics and Business Association for comment.