Madrid Addresses Media At Seffner, Florida Sinkhole

Larry Madrid, PE, president of Madrid Engineering Group, Inc. and a Florida sinkhole expert, was requested
on March 1, 2013 to come to the site of a sinkhole at 240 Faithway Drive in Seffner, Florida after Jeff
Bush had fallen into the collapse feature the night before. The Florida sinkhole was initially identified by Bill
Bracken, a structural engineer who is also trained as a first responder with Hillsborough County Fire
and Rescue who were some of the first on the scene. Bracken had initiated efforts to determine the
extents of the sinkhole when Hillsborough County asked for a third-party sinkhole expert to review
the methodology. Madrid reviewed CPT (cone penetrometer test) logs, electrical resistivity transects
and ground penetrating radar results, along with reports from rescue personnel who had indicated the
approximate size and shape of the hole at various times within the previous 18 hours. Soils information
indicated very loose sand to a depth of about 25 feet, underlain by very soft clay and clayey sand to a
depth of 57 to 67 feet where limestone was presumed to have been tagged by the CPT equipment.

After receiving a thorough briefing of the engineering data that had been gathered to that point,
Mr. Madrid participated in a private update of information to the immediate family and neighbors,
followed quickly by a press release to the media during the 6 o’clock news hour. The update consisted
of presentations by the Assistant County Manager Mike Merrill; Fire Chief Ron Rogers; Deputy Douglas
Duvall who had rescued Jeremy Bush (Jeff’s brother); Mr. Bracken and Mr. Madrid.

This tragedy is the only known death of a person being swallowed by a Florida sinkhole. In all previous
cases where a house or other building has been damaged by a collapse sinkhole, it is believed that
warning signals of ground movement and the reaction of the building to the movement have resulted
in sufficient time for those in the building to move to safety, or that the building was unoccupied at the
time of the collapse event.

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