Workers found acid bubbling from three holes in the tanker around 5:30 a.m. in the Roper Train Yard at 2274 S. 600 West, setting off the all-day drama that at times had emergency officials helplessly watching as thousands of gallons of acid seeped into the ground.
By late Sunday night - after hours of confusion, miscommunication and finger-pointing - residents were allowed to return home around 10 p.m. At the same time officials said they hoped the closed roads and Interstate 15 would be reopened within hours.
Special equipment was brought in from Las Vegas around 10 p.m. to pierce the tanker and drain the liquid into other containers - a race as the chemicals ate away at the railroad car and threatened to turn the leak into a flood.
More than 100 emergency crews from as far away as Tooele responded to the chemical spill, which they were initially told was composed of sulfuric, nitric, hydrofluoric and hydrochloric acids. The chemicals are dangerous on a number of levels - any one of them could burn the skin on contact, and if inhaled could damage the lungs, esophagus, cause difficulty breathing, nausea and vomiting.
Late in the operation authorities were surprised to learn the mixture may have been different than originally reported and may have included phosphoric, vinegar, ammonia.
"We're still concerned that is not what is on board," South Salt Lake Fire Chief Steve Foote said.
Fire officials said the rail car's manifest indicated it was carrying sulfuric and hydrofluoric acids to Ohio. But nothing other than sulfuric acid should have been in the tanker, according to the car's owner, Kennecott Utah Copper.
"Our contract is specific: That it is to be for sulfuric acid transport - that's what the car is designed for," said Kennecott spokesman Louie Cononelos. "Undeniably, there is something in there that is not compatible with the design and specifications of how that car is supposed to be used,"
Kennecott has a rail fleet of about 800 cars - about 100 of which are normally leased or subleased to other companies at any given time, Cononelos said.
Cononelos said a Fernley, Nev.-based agent from Philip Services Corp. subleased three cars owned by Kennecott in mid-February.
The two other tanker cars leased by Philip Services Corp. were stopped in Ohio after the leak in South Salt Lake. Kay Phillips, night duty officer for the Ohio Management Agency, said that as of late Sunday, there had been no reports of a chemical spill in the Buckeye State.
Among other services, the Houston-based Philip moves industrial waste and toxic chemicals throughout the United States. In doing so, the company's Web site pledges to protect "public health, safety, and the environment in the communities in which we operate."
In 2000 the company - which also specializes in cleaning chemical spills - was fined by the Environmental Protection Agency for failing to report an accidental discharge of approximately 641 pounds of nitrogen dioxide gas, which injured several workers in Tacoma, Wash.
In 2002, the EPA and Washington Department of Ecology levied more than $1 million in fines against the company "for repeatedly mismanaging dangerous wastes." Philip subsequently agreed to close a hazardous waste facility in Georgetown, Wash., that had spilled thousands of pounds of chemicals into a local watershed and was blamed for making residents sick.
Among the EPA's findings in the 2002 case: Incompatible wastes were stored too close together, increasing the possibility of a chemical reaction and waste materials were improperly stored in areas not allowed under the company's permit.
Philip officials could not be reached for comment Sunday night.
Gov. Jon Huntsman Jr. visited the spill sight around 8 p.m. Sunday to thank the crews and check on cooperation. He said he was troubled by the confusion.
"We're going to follow up and make sure we don't have that miscommunication again," he said.
Early on, authorities closed 600 West from 2100 South to 2700 South; northbound Interstate 15 from 4500 South to 2100 South, the westbound Interstate 80 off ramp to southbound I-15, and the southbound collector on I-15 up to westbound I-80 also were closed.
By late afternoon, residents and business people between 600 West and West Temple and 2300 and 2700 South were told to leave the area, said South Salt Lake Fire Chief Steve Foote. Residents and businesses between 2700 and 3300 South to West Temple could stay, but were told to stay inside and turn off their ventilation units to help avoid contamination.
The evacuation was ordered after authorities called off a plan to send a hazardous material specialist to siphon off the chemicals using a hose. That plan was scrapped when heat inside the car caused by the chemicals mixing with the carbon steel car began formed white, softball-size bubbles around the cars seam.
Authorities worried the chemicals were corroding the car to quickly and could dump the 10,000 gallons of acid into the yard. A spill that large could cause potential contamination to ground water, authorities said. At that point, the plan was to wait for the tanker to spill its contents and mop up the site.
With the new equipment from Nevada diffusing the situation, officials expected to work through the night excavating the contaminated dirt, about 60 feet by 100 yards.
The FBI investigated the scene and determined the leak wasn't linked to any type of terrorist or criminal activity. Authorities ruled out the possibility that the three holes were bullet holes. Foote later said the leak appeared to be a failure of the tank caused by acid that got between the inner tanks rubber lining and the tank itself, which is seven-sixteenths of an inch thick.