Crews will detonate a damaged 150-foot section of the bridge over Tempe Town Lake on Sunday. 

The work will be conducted along the south side of the lake between Tempe Town Lake and Rio Salado Parkway between 7 and 9 a.m. Sunday, according to Tempe Fire Department Assistant Chief Andrea Glass.

Glass said the detonation will sound like fireworks. 

Residents located to the south of the area will be asked to evacuate during that time. 

Chemical exposure causes injuries to one worker

Two workers were exposed to a hazardous material Friday afternoon while offloading a train car days after it derailed over Tempe Town Lake, officials said. 

A 52-year-old man was splashed in the face with cyclohexanone while disconnecting a hose from the tank car filled with chemical. He was seriously injured and taken to a hospital, Glass said.

The second worker was splashed in the chest with the chemical, treated on the scene and declined a ride to the hospital, Glass said.  

Cyclohexanone is a colorless industrial chemical used as a solvent in metal degreasing, manufacturing nylon and for thinning resins and lacquers.

Two of the cars that derailed contained the chemical. The cars had been removed from the bridge area so workers could transfer the chemical.

The contract workers started to remove the chemical from the first train car around 1:30 p.m. when they were splashed. Around 10 gallons of the chemical spilled into the soil before the leak was contained. 

All three cars were projected to be removed from the area by Sunday, but the incident slowed clean-up operations by another one to three weeks.

Tempe Mayor Corey Woods also signed an emergency declaration on Friday for the derailment. The declaration will give the city access to more funding. 

Tempe Town Lake and Tempe Beach Park remain closed for an unknown amount of time. Other activities at the lake have also been canceled, according to the city of Tempe. 

Train derails, engulfs in flames

Eight to 10 cars carrying lumber and hazardous material derailed around 6 a.m. on a railroad bridge over the Tempe Town Lake Wednesday morning. 

The 102-car Union Pacific freight train engulfed in flames on the more than 100-year-old bridge causing the structure to partially collapse on the south end. 

Two of the three cars that collapsed on the bridge were carrying cyclohexanone. One tank car leaked 500 gallons of the chemical after derailment before officials secured the car Wednesday night, according to Tempe Fire and Medical Chief Greg Ruiz.

No one was injured by the flames, but fire officials said one person was treated for smoke inhalation.

Contact the reporter at helena.wegner@arizonarepublic.com or on Twitter @WegnerHelena.

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