Just Sunday, as many united to remember the lives lost during the attacks of 9/11 ten years prior, U.S. Customs and Border Protection Port Director Michael Freeman warned citizens to always stay alert.
"I urge you to remain vigilant against any potential future attacks," Freeman said.
"This is the reality of our job, of every minute, of everyday."
A few hours later, at about 8 p.m., the Cameron County Sheriff's Department received the first of three bomb threat calls, at the Brownsville Matamoras International Bridge.
Traffic was diverted for about 30 minutes, with no explosives found.
Less than 24 hours later, on Tuesday morning, local and federal authorities responded to simultaneous bomb threats at Veteran's International Bridge and at Los Indios Bridge.
"We take every single call seriously and it's our job to protect the people and to make sure that everything is ok and that everybody is safe," Sheriff Omar Lucio said.
"(The caller) said, 'well you're going to see that we're going to blow you up whether you believe it or not."
A K-9 searched through Veteran's Bridge and traffic was diverted at both bridges for about 30 minutes - once again, no bombs turned-up.
However, Lucio said it didn't end there.
"The individual that called earlier has been calling about four or five times," Lucio said.
"Apparently he needs some help or some counseling or appears to have, according to the dispatcher, may have a mental problem."
Lucio said he was thankful no one was injured, but added that the calls do prove costly.
"It's unfortunate because it does stop traffic and it does put a lot of people to do something, where we could be doing something else instead of answering what we sometimes call prank calls," the sheriff said.
Lucio agrees with Freeman, and said whether it's prank or not, authorities must be prepared to handle certain types of situations on a daily basis.
"That's part of our job and we're going to do it," Lucio said.