A string of police-involved shootings this summer led to nationwide protests — NY1's Cheryl Wills looks back at the national headlines in Part Three of the National Year in Review.

Racial tensions boiled over in the summer of 2016, as a number of police-involved shootings sparked nationwide protests.

On the day after Independence Day, cellphone video captured officers shooting an unarmed man named Alton Sterling. The Louisiana incident prompted the Department of Justice to launch a federal investigation.

The following day, July 6, a police officer gunned down Philando Castile during a traffic stop in Minnesota. The graphic video ignited a public outcry. The governor of that state called for a federal investigation.

As Black Lives Matter protests ensued in Texas, a sniper identified as Micah Xavier Johnson assassinated five Dallas police officers on July 7 in the deadliest incident for law enforcement since 9/11. The gunman was later killed by a C-4 bomb. It was the first use of robotic lethal force by police in the United States.

In December, the high-profile shooting of Walter Scott ended in a mistrial. South Carolina prosecutors vow to retry former police officer Michael Slager.

There was anguish this summer in a Texas town, when a hot air balloon hit power lines and crashed, killing all 16 people onboard. Investigators later found that the pilot had seven different drugs in his system at the time.

Excessive speed was behind a commuter train crash in Hoboken that killed one person and injured more than 100 others in September. The engineer suffered from an undiagnosed sleep apnea.

A fast moving fire in an Oakland warehouse, known as The Ghost Ship, killed 36 people during a party in December. California authorities now say the venue had not been inspected for decades.

The last American born in the 19th Century died on May 12. Susannah Mushatt Jones of Brooklyn was 116 years old and reigned as the oldest person in the world.

And the 108-year curse was broken this year as the Chicago Cubs won the World Series, their first MLB title since 1908.