But inspectors would not necessarily check for such mechanisms, and it's not known whether they did when the West plant was last inspected in 2006, said Ramiro Garcia, head of enforcement and compliance.
That inspection followed a complaint about a strong ammonia smell, which the company resolved by obtaining a new permit, said the commission's executive director Zak Covar. He said no other complaints had been filed with the state since then, so there haven't been additional inspections.
At the church service, the Rev. Ed Karasek told the hundreds gathered that it would take time for the community to heal.
"Our hearts are hurting, our hearts are broken," he said. The non-denominational gathering for prayer and song was intended to honor those who rushed toward the danger and those who found themselves too close.
"I know that every one of us is in shock," he said. "We don't know what to think."
"Our town of West will never be the same, but we will persevere."