BOSTON, MA - APRIL 15: A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images)

MIAMI (CBSMiami) – The deadly attacks in Boston Monday left a city and a nation searching for answers. But it has also drawn attention to an odd historical phenomenon that happens around this time of April.

April 15 will be forever linked with the horrific bombings in Boston during the Boston Marathon. At least three people were killed and another 144 were injured during the bombings. April 16, 2007 was the date of the Virginia Tech University massacre where Seung-Hui Cho shot 32 students and faculty to death and injured 23 others before committing suicide.

April 17 is linked in many South Floridian’s minds with the failed Bay of Pigs invasion in 1961. The goal of the Bay of Pigs was to take over Cuba and get rid of Fidel Castro. The invasion, financed and trained by the CIA, ended up in disaster for the United States and drove the wedge even deeper with Cuba.

On April 18, 1983, a terrorist attack by a suicide bomber destroyed the U.S. Embassy in Beirut, Lebanon killing 63 people. In the U.S., April 18, 2012 also marked the end of a legendary era when Dick Clark passed away.

San Francisco will also forever remember April 18, 1906 when a magnitude 7.8 earthquake rocked Northern California. Approximately 3,000 people died and most of San Francisco was flattened by the quake. Fires through the city spread for two days after the earthquake.

April 19, 1995 started out like any other spring day in Oklahoma City, Oklahoma. But shortly after 9 a.m. local time, a Ryder truck exploded in front of the Alfred P. Murrah Federal Building in the worst case of domestic terrorism ever.

Timothy McVeigh was arrested and eventually executed for the bombing. The bombing on that April morning killed 168 people, including 19 kids in a day care in the building. More than 680 other people were injured during the blast.

McVeigh was upset over an even that happened two years to the day earlier on April 19, 1993. On that April day, the Branch Davidian compound in Waco, Texas burned to the ground after a 50 day standoff.

The Branch Davidians were led by David Koresh who was shot and burned along with 75 others when the government attempted to end the siege.

April 20 holds an infamous place in history for a number of reasons. On April 20, 1889, one of the most ruthless and evil dictators in history, Adolf Hitler, was born in Austria. Hitler would be responsible for the Holocaust and the murders of more than six million Jews along with millions of other political opponents.

The fact that April 20 was Hitler’s birthday played a role in a horrific event in American history in 1999. On that April day, Dylan Klebold and Eric Harris walked into Columbine High School in Colorado and opened fire killing 13 people and injuring 24 other before both committed suicide. Klebold and Harris reportedly chose the date because it was Hitler’s birthday.

Just three years ago, on April 20, 2010, another infamous event took place that rocked the entire Gulf coast of the United States. It was on that day the Deepwater Horizon oil drilling rig exploded. The explosion killed 11 workers and started an oil spill that lasted six months and devastated the Gulf of Mexico and the Gulf coast.

Finally, on April 22, 2000, one of the most controversial events in recent South Florida history took place when federal agents took six-year-old Elian Gonzalez from his relatives’ home in Miami. Elian was returned to the custody of his father in Cuba.