Deadly and coordinated attacks in Belgium were carried out at the Brussels airport and one of the capital's busy subway stations.
At least 34 people were killed and nearly 200, including several Americans, were injured.
The Islamic State has claimed responsibility for the attacks.
An airport security camera captured a photo of three men Belgian prosecutors say carried out the attacks. Investigators believe two men blew themselves up at the airport. The man is a wanted suspect.
The attacks come just days after Belgian police arrested a key suspect in last fall's deadly Paris terror attacks.
An explosive device, chemicals, and an Islamic State flag were found during the search of a home in Brussels Tuesday.
Twelve hours before those attacks, Tulsa's bomb squad sergeant, Jacob Thompson, was teaching a class of police rookies how to spot and deal with suicide bombers.
The Tulsa Police Department has seven bomb technicians and six bomb squad dog teams, and they train all the time for exactly what we saw overseas.
The bomb dogs are the first line of defense at the airport. TSA pays for them, but they're trained and handled by Tulsa police officers and are constantly searching public and private areas of the airport for explosive threats, especially public areas before you get to security, which is where the bombs went off in Brussels.
"We do patrol that public area. It's a big focus because of the vulnerability of that location; we even go out into the parking lot," Thompson said.
They have bomb robots to get an up close look at suspicious devices, technicians equipped with special suits and all kinds of tools to help them make devices safe.
But the most important thing is for people to pay attention and speak up if they see packages sitting around or weird behavior.
Thompson said, "Especially in today's society and culture, we don't want to offend or set off an alarm when it's nothing. You can tell when somebody's up to no good."
He said the key for law enforcement when it comes to bombers, is to act fast because hesitation can get officers and citizens killed.
The bomb squad goes on about 100 calls a year.