Question: Who committed the deadliest school massacre in United States history in 1927?

Context paragraphs:
Lullaby for Columbine: Lullaby for Columbine, Love Endures is the name of a benefit CD released in 1999 shortly after the Columbine High School massacre where twelve students and a teacher died in one of the deadliest school shootings in United States history.  The name is synonymous with both the title cut featured on the album and the non-profit organization that produced it, whose full name is "The Lullaby for Columbine Project."

Santa María School massacre: The Santa María School massacre was a massacre of striking workers, mostly saltpeter works (nitrate) miners, along with wives and children, committed by the Chilean Army in Iquique, Chile on December 21, 1907.  The number of victims is undetermined but is reliably estimated at over 2,000.  It occurred during the peak of the nitrate mining era, which coincided with the Parliamentary Period in Chilean political history (1891–1925).  With the massacre and an ensuing reign of terror, not only was the strike broken, but the workers' movement was thrown into limbo for over a decade.  For decades afterward there was official suppression of knowledge of the incident, but in 2007 the government conducted a highly publicized commemoration of its centenary, including an official national day of mourning and the reinterment of the victims' remains.

Oikos University shooting: The Oikos University shooting occurred on April 2, 2012, when a gunman shot at people inside Oikos University, a Korean Christian college in Oakland, California, United States.  Within a few hours, the number of reported fatalities reached seven.  43-year-old One L. Goh, a former student at the school, was taken into custody and identified as the suspect in the shootings.  Along with the California State University, Fullerton massacre, this was the fourth-deadliest university shooting in United States history, after the Virginia Tech massacre, the University of Texas Clock Tower shooting, and the Umpqua Community College shooting, and the eighth-deadliest U.S. school massacre overall.  It is also considered the deadliest mass killing in the city's history.

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.

Collinwood school fire: The Collinwood school fire (also known as the Lakeview School fire) erupted on March 4, 1908, killing 172 students, two teachers and one rescuer in one of the deadliest school disasters in United States history.

2011 Hackleburg–Phil Campbell, Alabama tornado: The 2011 Hackleburg–Phil Campbell, Alabama tornado was a violent, long-track EF5 wedge tornado that devastated several towns in northern Alabama, United States, before tearing through the northern suburbs of Huntsville and causing damage in rural portions of southern Tennessee on the afternoon and early evening of April 27, 2011.  It was the deadliest tornado of the 2011 Super Outbreak, the largest tornado outbreak in United States history.  The tornado reached a maximum width of 1.25 mi and was estimated to have had peak winds of 210 mph .  The tornado killed 72 people, making it the deadliest tornado in Alabama history, and injured at least 145 others.  It was the deadliest tornado to strike the U.S. since the Udall, Kansas tornado of 1955 until the catastrophic tornado on May 22, 2011, which killed 158 people in Joplin, Missouri.

Don Lee (politician): Don Lee (born 28 February 1960 in Blue Island, Illinois) was the state representative of District 28, consisting of the Columbine/Ken Caryl area of Jefferson County, Colorado, United States from 1998 to 2005.  Columbine High School is located within the district he represented.  He is best known for assisting victim parents from the Columbine High School Massacre in approving the "Respect Life" license plate, raising funds for victims of the Columbine High School Massacre as well as attempting to form an investigative committee to explore any "unanswered questions" about the attacks on Columbine and its aftermath.  Lee was reelected to his fourth term to the Colorado State House of Representatives in 2004 whereupon he promptly resigned therefore paving the way for a Republican vacancy committee to name Jim Kerr as his replacement.  He currently is vice president of government affairs for K12, Inc.

Elaine race riot: The Elaine race riot, also called the Elaine massacre, began on September 30–October 1, 1919 at Hoop Spur in the vicinity of Elaine in rural Phillips County, Arkansas.  With an estimated 100 to 237 blacks killed, along with five white men, it is considered the deadliest race riot in the state and one of the deadliest racial conflicts in all of United States history.  Due to the widespread white mob attacks, in 2015 the Equal Justice Institute classified the black deaths as lynchings in their report on lynchings in the United States.

2016 Orlando nightclub shooting: On June 12 , 2016, Omar Mateen, a 29-year-old security guard, killed 49 people and wounded 58 others in a terrorist attack/hate crime inside Pulse, a gay nightclub in Orlando, Florida, United States.  He was shot and killed by Orlando Police Department (OPD) officers after a three-hour standoff.  Pulse was hosting a "Latin Night" and thus most of the victims were Latinos.  It was both the deadliest mass shooting by a single shooter and the deadliest incident of violence against LGBT people in United States history.  It was also the deadliest terrorist attack in the United States since the September 11 attacks in 2001.

Bath Consolidated School: Bath Community School was a school in Bath Township, Michigan, USA.  It was the subject of the Bath School bombing on May 18, 1927, which killed 45 people and injured 58.  Most of the victims were children in the second to sixth grades attending the school.  This was the deadliest act of mass murder in a school in U.S. history.

Supporting paragraphs: Bath Consolidated School Bath School disaster
Answer: Andrew Kehoe