Editor's note: This version of the story has been changed to give the proper identity and attribution to Pat Brooks. He is the president of LMC Safety Barricade Corp., the company that provided the safety equipment for the work zone where Richard Slone was killed. It was Brooks, not Roanoke County Officer Mike Christian, who said the following: ''It's an absolute tragedy that a drunk driver would come through there and cause such mayhem.'' Another change clarifies a quote by Mike Flanary.

Roanoke County police have charged a second driver in the death of a Vinton construction worker that was caused by a chain-reaction crash early Wednesday morning.

Thursday, police charged Jeffrey Dupree, 32, with involuntary manslaughter in Richard Slone's death. Dupree already faced a charge of driving under the influence in the incident. His co-defendant, 42-year-old Tracie Nininger, was charged with involuntary manslaughter and driving under the influence shortly after the crash.

Police confirmed Thursday that before the wreck, Dupree and Nininger, who are both from Roanoke County, drank together at a downtown Roanoke bar.

Tuesday night, the two arrived separately at Cornerstone Bar & Grill, according to the bar's co-owner, Mike Flanary, who said he was not working that night but was given details by two bartenders and a doorman.

Dupree began drinking with some friends about 10:40 p.m. About 10 minutes later, Nininger entered the bar alone, Flanary said.

Nininger had a tab of about $22 that included a glass of wine and a round of shooters that she ordered for friends, Flanary said. Dupree and Nininger spent most of the next hour talking together before they left the bar.

"My bartenders told me that at the first sign she was impaired, she was handed her tab and was asked to leave," Flanary said.

Roanoke County police Officer Mike Christian said that two downtown bars are involved in the police investigation and confirmed that one is Cornerstone. Both restaurants have been very cooperative, he said.

Nininger left downtown in a Hummer H3 while Dupree followed in a Chevrolet Avalanche. About 12:30 a.m., Nininger was traveling on northbound Electric Road just past the intersection with Ogden Road when her Hummer struck a backhoe in a construction zone, Christian said. The backhoe was on the side of the road behind a dump truck. Dupree then hit the rear of the Hummer, Christian said.

Slone, who was standing beside the dump truck, was impaled against the truck by a plow attached to the backhoe, police said.

As the investigation into the wreck continued Thursday, Roanoke County investigators seized the sensory diagnostic modules from the Hummer and the Avalanche in hopes the data that the devices contain will shed light on what happened after the pair left the downtown bar.

Investigators with the Virginia Department of Alcoholic Beverage Control have offered to make themselves available to Roanoke County police, but as of Thursday afternoon, their services had not been requested, ABC spokeswoman Kristy Marshall said.

Though bars and restaurants in Virginia can be fined or have their ABC licenses suspended for serving alcohol to someone who is already intoxicated, if a patron leaves a bar and kills someone in a crash caused by driving drunk, under Virginia law the bar owners will not face any liability in the victim's death.

Though other states have laws that say an establishment can be held liable for a death caused by someone who drives drunk after being overserved at the bar, Virginia does not, said Benjamin Glass, a Fairfax personal injury lawyer who keeps a blog on legal issues.

The Supreme Court of Virginia has repeatedly held that the behavior of the driver is the source of liability in a drunken driving death, not the actions of the bar, even in cases where bars have illegally served minors.

According to Christian, Nininger had a blood alcohol content of 0.19 percent after the crash, more than twice the legal limit of 0.08. Dupree declined to take a test.

Both were being held Thursday evening in the Roanoke County-Salem Jail.

When he died, Slone was working a night shift for S.R. Draper Paving Co. Pat Brooks, the president of LMC Safety Barricade Corp., the company that that provided the safety equipment for the work zone, said that all safety procedures were followed and that it is the first time that he has had a worker die in a work zone in his 32 years in the traffic control industry.

The right-hand lane of Electric Road was closed from the Tanglewood Mall area through the intersection of Ogden Road. The drivers had gone 500 to 700 feet into the work zone before the accident, which happened in the zone's final 200 to 300 feet, Brooks said.

Brooks also confirmed that there were no apparent safety violations. The lane closures were easy to see, he said. "It's an absolute tragedy that a drunk driver would come through there and cause such mayhem."