Atmos Energy notified the city of Dallas that the company finished replacing all of the cast iron piping in its Dallas natural gas lines.

Why it matters: Federal regulators have warned about dangers of cast iron gas lines for years. Cast iron is more prone to explosions as it ages.

• A pipeline safety expert told WFAA that using such a brittle material to transport natural gas was “exposing the people in Dallas to a form of Russian roulette.”

Context: In February 2015, Dallas had 456 miles of cast iron piping in place, more than any other city in Texas.

• Most states stopped using similar pipes years ago.

Flashback: In 2018, a home in Northwest Dallas with cast iron pipes exploded, killing a 12-year-old girl. Two other homes on the block caught fire or exploded the same week.

• The tragedy prompted a series of investigations.
• At the time, Dallas County Judge Clay Jenkins requested a report from Atmos, saying that he wanted all cast iron pipes in Dallas out of the ground by the end of that year.
• Atmos said then that it could complete replacement by the end of 2023.

What they’re saying: “By partnering with our state regulatory agencies and local governments, we continue to make significant improvements to our infrastructure,” Atmos senior vice president Jeffrey Knights wrote in a letter to city leaders.