Every day, countless people in Mexico wake up to the sounds of a local gas vendor calling out that he has "Gaaaas!" for sale, or wake up to the projected sound of their local gas company's jingle, which is usually unique to each city.
Daniel Garcia is one of those vendors, delivering refilled LPG tank cylinders to customers in three central Mexico City neighborhoods, at about $25 for a 30-kilo tank.
"I wake up at 4:30," Garcia, a delivery man for a company called Gasomático, told VICE News on a recent morning. "And I start distributing at 6:30 am. My day ends around six at night."
During one of these early morning deliveries in the western Mexico City borough of Cuajimalpa, a gas leak caused an explosion that demolished a maternity ward at a public children's hospital. The blast on January 29 killed two nurses, two newborns, and a delivery man who was driving the LPG tanker and died of his burn injuries on Friday.
The blast has cast attention on the use of portable gas supplies in Mexico, the country with the highest per capita consumption of liquid petroleum gas worldwide, according to Mexico's energy ministry.
Eight in ten Mexican citizens use LPG in their homes to run their water heaters, ovens, and stoves.
Although Mexico's safety record for LPG distribution has been relatively sound over the years, major accidents such as the Cuajimalpa hospital blast and other gas-related disasters highlight the continued risks that come with gas delivery in Mexico.
In particular, the company at the center of the January 29 hospital explosion, Gas Express Nieto, has made headlines over the years for failing to comply with safety standards and for piling up consumer complaints.
The company is one of the four largest LPG providers in Mexico and reaches 80 percent of the country's territory, it said in a statement.
'Do you want a bomb under your feet?' propaganda signs on propane delivery trucks read for years after the Guadalajara disaster.
Between January and September 2014, Gas Express Nieto racked up 688 gas leaks nationwide — three of which occurred at schools, and one at a Mexico City day-care center — said the Mexican newspaper El Financiero.
In a July 2014 episode in the state of Querétaro, one of the company's gas tanker trucks crashed into a lamppost, engulfing five nearby vehicles and damaging ten homes. The blast killed a man and a seven-year-old girl, and injured a dozen others.
A Gas Express Nieto distribution truck similarly crashed into a lamppost in Mexico City in 2012. A nearby kindergarten had to be evacuated due to the escaping fumes, but no one was injured.
According to Mexico's energy secretary, the company has been found non-compliant in at least 94 safety inspections since 2011. From that year to 2014, safety failings were detected in 12 percent of inspections of Gas Express Nieto facilities.
The company currently has 436 open consumer complaints against it, according to Mexico's consumer protection agency, known by its Spanish abbreviation Profeco. An agency spokeswoman told reporters the company has been fined more than $1.3 million since 2013.
Gas Express Nieto has averaged at least one accident per year in the many states it services since 2008, according to government data.
The company "has a history of conflict," agency spokeswoman Lorena Martinez said. "It is a company that systematically refuses to be reviewed and additionally is highly litigious when it comes to the sanctions imposed on them."
In spite of these failures, Mexico City's health secretary Armando Ahued told VICE News that the local government in July 2014 renewed contracts granted to the company to serve a network of 29 government hospitals, including the one that was partially destroyed in the Cuajimalpa blast.
Today, half of residential consumers in Mexico purchase LPG in metal cylinders, while large stationary tanks filled by tanker trucks — like the one involved in the hospital blast — supply the remaining households.
Decades of government subsidies made it an accessible domestic fuel for the overall population, spiking Mexico's demand for the product. Less than 10 percent of households in Mexico rely on natural gas pipelines for domestic use, data shows.
Meanwhile, Mexico's recent energy reform is set to introduce more private companies — both foreign and national — into the energy sector in 2016, further expanding the need for proper safety controls and accountability, experts said.
It's not yet clear how the opening of Mexico's state oil sector will affect gas distribution in the country.
George Baker, a veteran observer of Mexico's energy industry, told VICE News the propane industry has "political protection" and has found ways to hinder proposals for building natural gas networks under Mexico's cities.
Past campaigns played in fears of combustibles being moved in underground pipes, the result of a 1992 sewer explosion in the city of Guadalajara that ripped up residential streets, damaged or destroyed hundreds of homes, injured thousands, and killed an estimated 200 people.
"Do you want a bomb under your feet?" propaganda signs on propane delivery trucks read for years after the Guadalajara disaster.
"Mexico City could have had a much safer natural gas pipe to that hospital if the propane distributors weren't so politically protected," said Baker, publisher of analyst site Energia.com.
VICE News requested an interview with the head of the liquid petroleum sector for Mexico's energy ministry, to ask why companies repeatedly labeled "non-compliant" during safety inspections continue to operate in Mexico, and what sort of restrictions or sanctions are placed on such companies.
"All of the doubts will be resolved after the investigations are finished," energy ministry spokesman Alberto Fieytal said, referring to the hospital blast inquiry.
Last month's hospital tragedy led many in Mexico to recall the 1984 San Juanico disaster, in which several state-owned LPG storage receptacles exploded into fireballs that engulfed an impoverished community on the outskirts of Mexico City.
The ensuing blast, which killed hundreds of people, although figures remain imprecise, is often called the worst LPG disaster in history.
"I think most people agree that the LPG is the least safe," energy analyst David Shields said. "Natural gas is lighter than air. It's basically methane, so it disperses more easily, but LPG can be very heavy, so it doesn't disperse as easily."
"What is obviously true is that these industries or these companies are kind of local monopolies, and so, like most businesses, they try to protect their local monopolies," Shields added. "That's what businesses do."
'If there's a leak we just close the tank, or we turn the tank over, because gas is heavier than air.'
But the Guadalajara tragedy is not the only major fatal incident blamed on a natural gas leak in recent years in Mexico.
In January 2013, shortly after current President Enrique Peña Nieto took office, an underground explosion at the skyscraper headquarters of state oil company Pemex was blamed by a government investigation on a methane leak.
Thirty seven people were killed, and critics raised doubts about the veracity of the government's claim of a methane leak.
Garcia, the delivery man, has worked as a gas distributor for the past ten years. He said he has never personally seen a leak-related catastrophe, but has seen accidents.
"Coworkers have crashed, but nothing worse has happened," Garcia told VICE News.
"When the tanks are old they start to get holes in the bottom, so we call leak control and they come get the cylinder," Garcia explained. "If there's a leak we just close the tank, or we turn the tank over, because gas is heavier than air."
"The tankers are much more dangerous, because they store more gas," he went on. "Periodically, the energy secretary, Profeco, or civil protection, come to check all of the security measures, extinguishers. They give us training every two years, how to detect a leak, what to do if you smell a leak."
It is unclear what sort of resolution will be reached for the victims of the Cuajimalpa hospital tragedy. The Mexico City government is coordinating talks between Gas Express Nieto and the families of those affected by the blast to determine compensation, an official statement said.
At least a dozen people remain under medical care following the accident.
David Agren and Daniel Hernandez contributed to this report.