LAKE ZURICH, Ill. (CBS) — This coming Sunday marks a painful anniversary in Lake Zurich.

As WBBM Newsradio’s Regine Schlesinger reports, Sunday will mark one year since an 18-year-old girl was killed when she and two friends were mowed down by a hit-and-run driver.

LISTEN: WBBM Newsradio’s Regine Schlesinger reports

Gabriella “Gabby” Drozdz and her friends were on their way to the annual Alpine Fest in Lake Zurich when a two-tone sport-utility vehicle – either a Chevrolet Astro or a GMC Safari – hit them in the 100 block of Church Street and kept going.

Drozdz died of her injuries. Two friends were also hit by the car, but survived.

Her sister, Ilona Gregory, says time is not easing the grief.

“Very difficult to go through the first – it’s always the first milestones, you know, like Christmas, and her birthday, and all of our birthdays,” Gregory said.

Lake Zurich Police Cmdr. David Bradstreet hopes the first anniversary of Drozdz’s death will help generate some new leads.

“We’ve checked all of Lake County, parts of McHenry, northern Cook, Kane County – we’ve just been everywhere looking for this vehicle,” Bradstreet said.

Police will be out at Alpine Fest this weekend, passing out fliers about the case. Drozdz’s family, meanwhile, will hold a special mass in her memory.

“We try to focus on the positive, and all the joy and the light that she brought into our lives,” Gregory said.

Police say the van that hit Drozdz is a two-tone van, blue with a second lighter color, possibly silver or gray.

The models could have possibly been made between 1985 and 1994, and police say the vehicle involved in the hit and run would have damage to the side turn signal and marker li