Sean Copeland, 51, and 11-year-old Brodie are among the dead in Nice, France, following the Bastille Day attack
Credit: Source: Brian Spyros/Twitter

A Texas father and son were among the 84 killed in Nice, France, on Thursday after a truck drove into a crowd celebrating Bastille Day in the city, according to multiple reports.

Sean Copeland, 51, and his 11-year-old son Brodie were killed in the attack while on vacation in the seaside city with family, a friend of the family told CBS News.

“We are heartbroken and in shock over the loss of Brodie Copeland, an amazing son and brother who lit up our lives, and Sean Copeland, a wonderful husband and father,” the family said in a statement issued by the friend. “They are so loved.”

The Copelands live in Lakeway, an Austin suburb, according to NBC News.

Haley Copeland, who identified herself as the elder Copeland’s niece, confirmed the deaths in a Twitter post and noted that the family was on vacation.

“This is an extremely difficult time for my family and anyone who knows Sean and Brodie Copeland,” the woman wrote. “Losing a loved one is hard no matter the circumstances but losing a loved one in such a tragic and unexpected way is unbearable.”

State Department spokesman John Kirby confirmed that two Americans died in a statement to PEOPLE, but did not name the father and son.

“We express our sincere condolences to the family and friends of those killed,” Kirby said in the statement. “Our embassy in Paris is making every effort to account for the welfare of U.S. citizens in Nice. Any U.S. citizens in Nice should contact friends and family directly to inform them of their well being.”

An FBI source tells PEOPLE: “There are approximately 20 Americans known to be in the area of Nice who are still unaccounted for. That’s not to say they were involved in this event. Just that we have 20 Americans unaccounted for.”

Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Brodie played youth baseball and his father coached, according to the Austin American-Statesman.

Officials with the local Hill Country Baseball team took to Facebook, posting a tribute to the pair.

“Nobody deserves this type of fate, especially not such a wonderful family,” the post read. “You are in our hearts, thoughts and prayers. Rest in peace, Brodie and Sean, you will be remembered by many.”

Among the more than 80 deaths, 120 people are said to have been injured in the attack. The truck zigzagged as it barreled more than a mile through the crowd, according to a report from France 2.

Local news outlet, Nice-Matin reported that the vehicle ran through the crowd as dozens watched a fireworks display on the Promenade des Anglais, according to NBC News

The driver of the vehicle was fatally shot, French President Francois Hollande confirmed at a press conference.

“Horror again here in France,” Hollande said. “France as a whole is under the threat of Islamic terrorism. … We have to demonstrate absolute vigilance and show determination that is unfailing.”