7.3 Damage to Utilities
65
be intact it might well be damaged or weakened by the explosion. Not only that, but
a pipe (for example) that had been supported along its length by the soil or trench
in which it had rested will now be unsupported across the diameter of the crater;
this places additional stress on the line that can cause it to fail, causing additional
dangers.
• Electrical lines can create electrocution hazards at the site of the break as well as
in any location that is electrically connected to the line (e.g. a pool of water or
length of metal rebar). In addition, damage to electrical lines can cause longerterm public health problems and can impair response efforts until generators can
be brought to the scene.
• Steam line ruptures can cause serious burns from leaking steam. In addition,
many steam lines were once insulated with asbestos-bearing lagging and steam
line ruptures have introduced asbestos into the atmosphere and surrounding areas.
• Water and sewer line ruptures can cause flooding, can undermine pavement leading
to later collapse, and can raise public health concerns in the days, weeks, or months
following the explosion. Damage to water lines might also impair fire-fighting and
decontamination or contamination control efforts.
• Natural gas line ruptures can ignite or explode (especially if they are in proximity
to downed or ruptured electrical lines), posing a serious threat to the health of
anyone in their vicinity. This can also deprive those living in the area of heat, hot
water, and the ability to cook until the lines can be repaired.
• Subway lines, pedestrian tunnels, utility access tunnels, and the like can be
breached, weakened, or collapsed. This can put people at risk directly and can also
make it possible for groundwater to flood the tunnels over a longer period of time.
In addition, because subways are generally electrically powered, and any tunnels
meant to be accessed by members of the public will be lighted, there will be electrical lines running through the tunnels that can be damaged or short-circuited by
water flooding the tunnel, causing additional risks to people who might be in the
tunnels or who might enter in order to conduct emergency response activities.
Thus, not only do damaged or ruptured utility lines pose a risk at the site of the
attack, but the loss of these utilities can also complicate emergency response efforts in
the short term and can lead to longer-term public health concerns for those affected.
7.4 Fires
As noted above, natural gas lines can rupture and ignite, causing fires, but the explosion itself can also ignite fires. Having said this, high explosives (those in which
the detonation velocity is greater than the speed of sound) “are primarily intended
to cause damage through blast and…fragmentation” [8] and are less likely to ignite
fires compared to low explosives such as black powder or ANFO (ammonium nitrate
mixed with fuel oil) or explosives that consist of fuel sprayed into the air and ignited.
65
be intact it might well be damaged or weakened by the explosion. Not only that, but
a pipe (for example) that had been supported along its length by the soil or trench
in which it had rested will now be unsupported across the diameter of the crater;
this places additional stress on the line that can cause it to fail, causing additional
dangers.
• Electrical lines can create electrocution hazards at the site of the break as well as
in any location that is electrically connected to the line (e.g. a pool of water or
length of metal rebar). In addition, damage to electrical lines can cause longerterm public health problems and can impair response efforts until generators can
be brought to the scene.
• Steam line ruptures can cause serious burns from leaking steam. In addition,
many steam lines were once insulated with asbestos-bearing lagging and steam
line ruptures have introduced asbestos into the atmosphere and surrounding areas.
• Water and sewer line ruptures can cause flooding, can undermine pavement leading
to later collapse, and can raise public health concerns in the days, weeks, or months
following the explosion. Damage to water lines might also impair fire-fighting and
decontamination or contamination control efforts.
• Natural gas line ruptures can ignite or explode (especially if they are in proximity
to downed or ruptured electrical lines), posing a serious threat to the health of
anyone in their vicinity. This can also deprive those living in the area of heat, hot
water, and the ability to cook until the lines can be repaired.
• Subway lines, pedestrian tunnels, utility access tunnels, and the like can be
breached, weakened, or collapsed. This can put people at risk directly and can also
make it possible for groundwater to flood the tunnels over a longer period of time.
In addition, because subways are generally electrically powered, and any tunnels
meant to be accessed by members of the public will be lighted, there will be electrical lines running through the tunnels that can be damaged or short-circuited by
water flooding the tunnel, causing additional risks to people who might be in the
tunnels or who might enter in order to conduct emergency response activities.
Thus, not only do damaged or ruptured utility lines pose a risk at the site of the
attack, but the loss of these utilities can also complicate emergency response efforts in
the short term and can lead to longer-term public health concerns for those affected.
7.4 Fires
As noted above, natural gas lines can rupture and ignite, causing fires, but the explosion itself can also ignite fires. Having said this, high explosives (those in which
the detonation velocity is greater than the speed of sound) “are primarily intended
to cause damage through blast and…fragmentation” [8] and are less likely to ignite
fires compared to low explosives such as black powder or ANFO (ammonium nitrate
mixed with fuel oil) or explosives that consist of fuel sprayed into the air and ignited.