Breaking: The death toll is uncertain at a Mexico City children's hospital that has been collapsed by a gas pipe explosion

A gas pipe that exploded shortly after 7:00 a.m. this morning has virtually collapsed a children’s and maternity hospital in the Cuajimalpa borough of Mexico City.
    Newspaper sites are reporting seven deaths, but Mexico City Mayor Miguel Ángel Mancera put the number of confirmed at two around noon.
    Federal government officials are asking for prudence in the citing of figures at this point. Rescue efforts are ongoing. The number of injured is so far reported at more than 60.
    At least one emergency vehicle was on site before the explosion after a gas leak had been detected. The blast was caught on video, which leaves no doubt about how powerful it was.
    President Enrique Peña Nieto promised federal help. Mancera and Interior Secretary Miguel Ángel Osorio Chong arrived at the hospital later this morning.
    The navy sent explosives experts to the site. The news reached Pope Francis quickly. He sent prayers through his Twitter account.
    Some of the injured were taken to the Santa Fe campus of the ABC Hospital. Blood donors are urged to give at that site.
    The gas blast at the Hospital Materno Infantil was not the first in recent Mexican history. There have been eight major events in the last 30 years. Three examples:
    On November 19, 1985 a chain of gas explosions in the San Juanico neighborhood in the State of Mexico outside the capital claimed about 500 lives.
    On April 22, 1992, 210 people perished from andexplosion and resulting fire along a gas line in Guadalajara.
    Most recently, on May 7, 2013, a gas truck’s tank exploded on a highway near Mexico City, leaving 20 dead, 36 injured and 45 dwellings damaged.