1 - The Black Vault

major eruption occurred. Seismographs on the
mountain were now recording approximately 300
tremors each day, which indicated a growing instability
inside the mountain. Hess brought his
staff together and reviewed possible options.
Wing leadership had the difficult decision of
separating military members from their families
if the aircraft were evacuated. The 353d SOW
was unique in that most of its personnel were on
accompanied tours, and its military members had
their families with them (most other military
personnel in the Philippines were on 12-to-24
month unaccompanied tours). After the third
eruption on the morning of 13 June, it appeared
almost certain that the 353d SOW aircraft would
have to be evacuated further from the volcano.
Aircrews had flown throughout the previous
night and were not in shape for another launch
at that time. Hess decided to put all of his fixedwing
crews in crew rest, and he arranged to have
the MH-53J helicopters hangared at Cubi Point. 13
In the early morning hours of 14 June, a brief
period of clear weather offered a good look at the
mountain. Although long-period earthquakes had
intensified throughout the preceding 24 hours,
there was little visible ash and plume being emitted
from the summit at that time. During the afternoon
of 14 June, after 28 hours without a major
eruption, activity picked up and continued to accelerate
throughout the evening hours and on into
the early hours of 15 June. With an additional
threat posed by Typhoon Yunda, Hess ordered the
evacuation of the two MC-130E Combat Talons,
the C-130E slick, and the C-130H aircraft to
Kadena AB. By late evening on 14 June, all fixedwing
aircraft had departed the Philippines, with
the MH-53s remaining hangared at Cubi Point.
Mount Pinatubo continued to increase its activity,
and evidence mounted that there were eruption
clouds venting from two different locations on the
mountain.* 14
At dawn on 15 June, PVO volcanologists were
able to observe a huge ash cloud as Mount Pinatubo
exploded for the fourth time at 0555 local. Unlike
the tall narrow columns of ash formed during the
12 and 13 June eruptions, the 15 June eruption
produced a relatively low ash cloud that spread
out laterally rather than vertically from the volcano.
This development raised concern that the
volcano’s summit could collapse, thus causing lateral
blast and pyroclastic flow during future eruptions.
The lateral blast could be directed toward
MOUNT PINATUBO TO OPERATION JOINT ENDEAVOR
Clark AB. Consequently, most remaining personnel
at Clark AB were directed to evacuate and
seek safety further to the east. 15
Until 15 June Cubi Point had escaped any serious
affects from the volcano due to favorable
winds carrying ash to the west over the South
China Sea. Luck was about to change, however,
as Typhoon Yunda continued to build off the
eastern coast of Luzon. The storm moved relentlessly
to the west, and by 0930 local on 15 June,
its eye was directly over Subic Bay. Typhoon
Yunda was producing 40 to 50 kilometer winds
and heavy rains. The most devastating effect of
the typhoon, however, was its northwest winds
that carried ash from Mount Pinatubo toward
Subic Bay and Cubi Point and then on towards
Clark AB, by 1000 local the sky was completely
dark. Mallon described the darkness as that
found in a “sealed closet,” with exploding elect
rical transformers the only light in the blackness.
The continuous earthquakes struck fear
into everyone, compelling some to seek safety outside
in the event of building collapse. But outside,
blizzard-like ash and a surreal electrical storm
created by the exploding transformers were more
frightening than the danger of collapsing buildings.
16
Throughout the remainder of the morning and
into the early afternoon, volcanic activity continued
to increase. By 1430 all but one of the PVO
seismometers were inoperative, which was prob -
ably due to pyroclastic flow. Ash, with large pumice
fragments, was falling on Clark AB. In all
probability the climatic eruption was under way
by this time, but the volcano could not be ob -
served visually due to total obscuration of the
mountain, nor could it be monitored electronically
due to the loss of the seismometers. At that time
all remaining personnel evacuated Clark AB, including
Stankovich’s team, and moved to Pampanga
Agricultural College—about 38 kilometers
east of Mount Pinatubo. 17
The events of 15 June were a living hell for
anyone caught in the maelstrom created by the
typhoon and the exploding volcano. Many of the
1st SOS dependents left behind after the 14 June
aircraft evacuation were housed in the Marmont
Hotel off base, and by 2100 three nearby buildings
had collapsed. Throughout the area more
than 200 buildings collapsed during the night due
to the tremendous weight of the rain-soaked ash.
Sergeant Kay, the 1st SOS first sergeant, and
__________
*PVO geologists north of the volcano saw two or more ash sources during increased activity on the afternoon of 14 June. At Clark AB a
thermal-infrared scanner recorded possible multiple vents during a 2320 eruption on 14 June.
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