A 14-year-old Fort McMurray girl has died two weeks after an all-terrain vehicle crash that left her and another teen in critical condition.

The girl died Saturday in the Edmonton hospital where she had been since the accident.

The incident happened on the May long weekend, apparently after a late-night party.

The girl was driving the quad, with a 17-year-old female passenger, when they struck a ditch and were thrown into a tree. Both teens had to be airlifted to an Edmonton hospital because of the severity of their injuries.

Police have said they are investigating whether alcohol was involved in the crash.

The incident has led to speculation in the community about why groups of young people were gathered in an area in the community's southeast at 3:45 a.m. Police are asking people not to jump to conclusions until their investigation is completed.

"With any incident we usually get some rumours spread or somebody seems to have come to a conclusion as to what's occurred," RCMP Const. Ali Fayad said.

"We're the investigators, and we are looking at the information that we have and we are trying to piece together the puzzle here. We just ask the people to leave that to the investigators and we will do a thorough job, and hopefully we will be able to piece that together." 

The 17-year-old injured in the crash is improving in an Edmonton hospital, Fayad said, but is still in serious condition.

The names of the ATV driver and passenger have not been released.