MEXICO CITY -- As rescue efforts were winding down Friday at Mexico's state oil company, where a blast the day before killed at least 33 people, workers gathered nearby, saying they were unafraid of going back to work and eager to do so as soon as they were told it's OK.
There would be no business at the tower complex until further notice. Yet on Friday, employees of Petroleos de Mexico, or Pemex, kept showing up. Some were eager to get inside to help with the rescue effort, while others said they were awaiting news of co-workers and friends who remained unaccounted for.
Armed soldiers were guarding all the entrances and exits of the complex. Rescuers from the army, marines, Mexican Red Cross, and the searchers known as topos were still clearing away rubble.
An estimated 10,000 people work at the Pemex headquarters in Mexico City. The workers described it as a cosmopolitan setting, with employees, contractors and visitors from all over Mexico and the world circulating through the building each day.
Carlos Pineda, 45, an accountant who has worked in the main Pemex tower for 10 years, said he was on the 10th floor when the blast occurred Thursday afternoon. Pineda said workers in the buildings were prepared through previous drills to face an emergency such as an earthquake.
Pineda wouldn't speculate on what caused the blast in the basement of the building called B2, which he described as the human resources department, where there is "a lot of traffic."
"We're all asking ourselves the same thing, what happened?" Pineda said. "I really don't know what could have happened. These are administrative offices, not workshops. There are no solvents or anything like that."
Pineda and others said they wanted to know who was injured and who was killed. No official information has been released on the dead. He said he recognizes coworkers by faces but not necessarily by names.
Like others, Pineda said he's prepared to go back to work as soon as possible because Pemex is "so important to the country."
Marco Antonio Franco, a top search-and-rescue official at the Mexican Red Cross, said teams would keep looking as long as there was a possibility that people were trapped under rubble.
"A young man just came up and said he still can't find his father, he went to the morgue, and to all the hospitals, and well that gives us the possibility that someone could still be under the structure," Franco said.
"Ground zero here looks a lot like an earthquake," said Franco, who was among Mexican rescue workers who traveled to Haiti for search efforts after the 2010 quake there.
Carlos Alberto Hernandez, a 38-year-old cleaner in the tower, stood outside an entrance to the Pemex complex waiting for his chance to get inside to help. Others milled about with worried expressions.
"That's why we're here, to support our coworkers, to help look for anyone who might be trapped or injured," he said. "I don't have any anxiety about going back to work, no. Anxiety maybe so I can get inside."
By the afternoon, the Red Cross was pulling out, and the search was being suspended.