UPDATED 12/14/11 6:18 a.m.

LAKE ZURICH, Ill. (CBS) — After initially saying a dump truck driver admitted to driving under the influence, police in Lake County said Tuesday that they are still trying to sort out who is to blame for a horrific crash that left a 10-year-old boy dead and his brother critically injured.

Police say the crash happened at 5:42 p.m. Monday at Rand and Old McHenry roads in unincorporated Lake County.

The twin boys, Griffin and Nicholas Shirey of Island Lake, were in a Lincoln sedan being driven by their father, Scott, 49, when a dump truck crashed into them.

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The one-ton Ford Super Duty dump truck, which was hauling roof shingles, was headed north on Rand Road when it broadsided the Lincoln, which was turning left in front of it, police said.

Both vehicles spun, and the truck flipped over, police said. A Ford Edge and a Chevrolet Cruze were also hit in the accident, but their drivers were uninjured.

The Lake County Sheriff’s Office said it’s too soon to assign blame for the tragic accident. As of Tuesday evening, police were still trying to determine if one of the drivers ran a red light.

Although police initially said one of the drivers admitted to driving under the influence of narcotics, Lake County Sheriff Mark Curran said Tuesday there are no indications that either drivers was impaired.

“We have no evidence of anyone being under the influence,” Curran said, adding that investigators are still awaiting test results of urine samples taken from two drivers involved in the 5:45 p.m. Monday crash.

Griffin and his brother were wearing seatbelts when their car was struck, Curran said.

Some witnesses reported the pickup truck driver didn’t stop for a red light at the intersection, Curran said.

“We have reports of the the truck running a red light and exceeding the speed limit,” Curran said.

The speed limit on the divided, four-lane highway is 55 miles an hour.

The truck driver was treated for minor injuries, then taken to Waukegan for questioning and later released. No charges have been filed against him, said Curran. He said the investigation into the crash is continuing.

The boys and their father were taken to Advocate Good Shepherd Hospital in Barrington, where Griffin was pronounced dead. Nicholas was later airlifted to Advocate Lutheran General Hospital in Park Ridge, where he was reported in critical condition with internal injuries, police said.

Scott Shirey was reported in stable condition at Good Shepherd, police said.

Tuesday night, investigators were still trying to determine if anyone was at fault, but the loss felt in Lake County was immediate.

“We are so sorry. We all miss … we all love Griffy and we’re just so sorry,” neighbor Kathy Berg said after learning of Griffin Shirey’s death. “We just pray that Nicky will be okay and we’v been praying for Griffy all day.”

The collision was so violent that the truck flipped after it smashed into the car. The intersection has seen its share of death.

The intersection where the crash occurred is the same intersection where a driver polishing her nails struck and killed a Lake Zurich motorcyclist in May 2009. The driver, Lora Hunt, rear-ended cyclist Anita Zaffke at a red light.

Hunt is now serving an 18 month night-time jail term that allows her to work during the day.

“That road’s a busy street and it’s a very dangerous intersection,” Berg said.

Lake County Sheriff’s Deputy Chief Kevin Parker said, “It’s horrific. There’s a 10-year old boy that lost his life and how does anyone deal with that grief? You know, it affects us all, especially those of us that are parents.”

It especially hits hard in the small community of Island Lake, where the boys lived and attended school. Berg said their block will never be the same.

“Both are adorable little boys and we’re just all very sad. The whole neighborhood is so sad. We all knew the boys,” Berg said. “The whole neighborhood’s praying for (the family). We send them our love and if they need anything … the whole neighborhood’s there for them and will come and do whatever they need.”

Wauconda School Supt. Dan Cole says grief counselors are on hand at Cotton Creek School, where Griffin was a fifth grader.

“He was a very good student in the classroom; very well-liked by his peers,” Cole said. “He’ll be greatly missed.”

The drivers of all four vehicles involved in the crash submitted to drug and alcohol tests. As of late Tuesday, investigators said they don’t believe drugs or alcohol contributed to the crash.

The Sun-Times Media Wire contributed to this report.