Question: The explosive Pyrotol was known for being used in a 1927 bombing commited by who?

Context paragraphs:
Bath School disaster: The Bath School disaster, sometimes known as the Bath School massacre, was a series of violent attacks perpetrated by Andrew Kehoe on May 18, 1927 in Bath Township, Michigan, which killed 38 elementary schoolchildren and 6 adults and injured at least 58 other people.  Kehoe killed his wife and firebombed his farm, then detonated an explosion in the Bath Consolidated School before committing suicide by detonating a final device in his truck.  It is the deadliest mass murder to take place at a school in United States history.

Pyrotol catalyst: Pyrotol is a catalyst used in the industrial production of benzene through a process known as pyrolysis.  It is a proprietary chromium-alumina catalyst manufactured by Clariant International (formerly known as Sud-Chemie) and licensed exclusively to CB&I Lummus Technology, Inc..  It is completely unrelated to the explosive pyrotol.

2004 Grozny stadium bombing: The 2004 Grozny stadium bombing occurred on 9 May 2004 when a bomb exploded in the Dynamo stadium in the Chechen capital, Grozny, killing 10 people including the republic's president Akhmad Kadyrov and another 100 people were wounded.  Kadyrov's election was considered by many to be by a fraudulent vote.  The explosion was caused by a bomb planted underneath the concrete floor of the VIP podium and occurred at 10:35am during a parade and concert in Groznyy celebrating the 59th anniversary of the victory of Germany in World War 2.  The blast tore a hole in the section designated for dignitaries.  It was not clear if the explosion was specifically targeting Kadyrov or whether it would have occurred regardless of his presence, as he was not officially scheduled to be at this event.  Khussein Isayev, chairman of the Republic's state council, and Adlan Khasanov, a reported for Reuters, were also killed in the blast.  Col. Gen. Valery Baranov, the commander of the Russian military in the northern Caucasus was gravely wounded.  Although estimates of total casualties varied, at least ten people were killed and around fifty more injured.  The numbers include many civilians and WW2 veterans who were also attending the celebrations.  Officials believe that the blast was detonated by remote control and was intentionally installed below the VIP section.  The bomb may have been planted some time ago during the recent renovations to the stadium.  Preliminary reports suggest that the bomb was equivalent to one ton of TNT.  The location of the bomb made it impossible for existing equipment to detect.  The type of explosive appeared identical to one used to blow up the military parade two years ago in the Dagestani city of Kaspiysk.  Rescue workers prevented two other blasts in the stadium.  They were able to defuse another landmine and an additional explosive device equipped with a timer set to go off 30 minutes after the first explosion.

1990 Tbilisi–Agdam bus bombing: The 1990 Tbilisi–Agdam bus bombing, also known as 1990 Khanlar bus bombing occurred on August 10, 1990, in the vicinity of Khanlar (now "Goygol") when an explosive devise blew up in a bus 12.5 km away from Ganja, Azerbaijan's second largest city.

Erythritol tetranitrate: Erythritol tetranitrate (ETN) is an explosive compound chemically similar to PETN.  It is however thought to be 1/3 more sensitive to friction and impact.  ETN is not well known, but in recent years has been used by amateur experimenters to replace PETN in improvised detonation cord or in boosters to initiate larger, less sensitive explosive charges.  Due to the availability of erythritol as a natural sweetener and its relative ease of production in relation to PETN, ETN is a favoured homemade explosive compound to the amateur experimenter.

MT explosive motorboat: The explosive motorboat MT ("Motoscafo da Turismo") also known as "barchino" (Italian for "little boat"), was a series of small explosive motor boats developed by the Italian Royal Navy, which was based on its predecessors, the prototype boat MA ("Motoscafo d'Assalto") and the MAT ("Motoscafo Avio Trasportato"), an airborne prototype.  Explosive motorboats were designed to make a silent approach to a moored warship, set a collision course and run into full gear until the last 200 or 100 yards to the target, when the pilot would eject after blocking the rudder.  At impact, the hull would be broken amidships by a small explosive charge, sinking the boat and the warhead, which was fitted with a water-pressure fuse set to go off at a depth of one metre.  By the end of September 1938 the Navy Department ordered six explosive boats.  The one-pilot vessels were built by the companies Baglietto of Varazze and CABI of Milan, which was also to supply the engines.  The small vessels were used by the Italian Navy in at least two major operations in the Mediterranean theatre during World War II.

High-explosive squash head: High-explosive squash head (HESH) is a type of explosive ammunition that is effective against tank armour and is also useful against buildings.  It was fielded chiefly by the British Army as the main explosive round of its main battle tanks during the Cold War.  It was also used by other military forces, particularly those that acquired the early post-World War 2 British 105 mm Royal Ordnance L7A1, including Germany, India, Israel and Sweden.  In the United States, it is known as HEP, for "high explosive, plastic".

Pyrotol: Pyrotol was an explosive available for a time after World War I.  It was reprocessed from military surplus.  Usually used in combination with dynamite, it created an incendiary blast.  Since it was very inexpensive, it was often used by farmers to remove tree stumps and clear ditches.  The substance was known for being used to commit the Bath School bombing in 1927 and distribution of pyrotol for farm use was discontinued in 1928 due to exhaustion of the supply of surplus explosives.

Acetone peroxide: Acetone peroxide is an organic peroxide and a primary high explosive.  It is produced by the oxidation of acetone to yield a mixture of linear monomer and cyclic dimer, trimer, and tetramer forms.  The trimer is known as triacetone triperoxide (TATP) or tri-cyclic acetone peroxide (TCAP).  Acetone peroxide takes the form of a white crystalline powder with a distinctive bleach-like odor and can explode if subjected to heat, friction, or shock.  As a non-nitrogenous explosive, TATP has historically been more difficult to detect, and it has been implicated as an explosive used in several terrorist attacks since 2001.

Bombing range: A bombing range is an area used for testing explosive ordnance and practicing to accurately direct them to the target.  Bombing ranges are used for munitions that either explode or produce too much destruction to use at a shooting range, such as kinetic energy penetrators or very large caliber bullets. Bombing ranges are usually used by highly organized military organizations.  Terrorists and rebels are likely to test weapons where most convenient and not use a strictly defined area because the explosions attract attention and long-term safety is not a consideration.

Supporting paragraphs: Pyrotol Bath School disaster
Answer: Andrew Kehoe