Crash on I-79 detours southbound traffic through Pittsburgh, snarls rush hour

A tractor-trailer rollover on a southbound Interstate 79 bridge and subsequent crash disrupted traffic for most of Thursday when police closed the highway and diverted motorists into Downtown Pittsburgh.

The truck crashed on a bridge over Route 51 near Neville Island about 9 a.m. The road did not reopen until about 5 p.m.

Within an hour of the crash, PennDOT officials closed the southbound lanes as far north as the Interstate 279 split, said Steve Cowan, a PennDOT spokesman. The road was closed into the evening rush-hour commute, adding to traffic through the city.

“We are talking about thousands of vehicles being detoured,” Cowan said.

The closure caused a 2-mile backup and another accident, said Trooper Robin Mungo of the Pennsylvania State Police.

Several miles north of the first accident, a Mercedes sport utility vehicle rear-ended an Acura SUV, Mungo said.

The Acura's driver, Ciana Marie Cahill, 21, of Wexford, was in critical condition with head injuries in Allegheny General Hospital, police said.

State police filed no charges related to either accident.

Mungo identified the truck driver as Barry Weems, 52, of Madison, Ohio.

Cowan said crews used a crane to remove the trailer from the road. Its contents, a filtration additive called Celite, spilled onto Route 51 below I-79, Mungo said.

Celite is used in filtration, liquid solid separation and as a filler in paints and coatings, according to Imerys Filtration, a Santa Barbara, Calif.-based manufacturer of the product. Emergency responders at one point wore masks to avoid breathing the dust.

The diverted traffic included many vacationers, Mungo said.

“There are several southern states (that) people travel to by starting on 79,” she said.

Rick Wills is a Trib Total Media staff writer. Reach him at 412-320-7944 or rwills@tribweb.com.