The second came about 90 minutes later when someone phoned in a bomb threat to the corporate offices of Fifth Third Bank in downtown Tampa.
Coincidentally, 30 officers were training their bomb-sniffing dogs at Raymond James Stadium at the same time authorities were shutting down traffic on Dale Mabry and evacuating the bank building.
How police responded to the two threats and how they trained Tuesday all tie in to the bombings at the Boston Marathon, authorities said.
“With what we’ve experienced since Boston, we’re more vigilant,” Tampa police spokeswoman Laura McElroy said.
Twelve local and federal agencies attended Tuesday’s training at the stadium. Among them was Tampa K-9 officer Tim Bergman and his 3-year-old German shepherd, Indo.
Bergman guided Indo through the corridors and Tampa Bay Buccaneers players’ locker room beneath the rafters, allowing the canine to sniff out substances used in explosives.
Indo found trace amounts of peroxide-based chemicals hidden by trainers and a 50-pound bucket of ammonium nitrate.
Bergman said he was in the midst of training when he was called to sweep the Fifth Third Bank building.
“We checked the 18th, 19th and 20th floors,” he said. “We did a lot of sweeps.”
Authorities found nothing. The call was a false alarm, McElroy said, and employees returned to work about 1 p.m.
McElroy said the last regional training session at the stadium took place before the Republican National Convention came to town in 2012. In light of what happened in Boston, the training is now scheduled every three months, she said.
Tampa police have seen a slight increase in bomb-related calls since the marathon and rescheduled officers’ shifts to deal with them.
“We’ve increased the number of bomb technicians and bomb dogs working each shift,” McElroy said. “We anticipated more citizens calling in because of suspicious packages.”
Police have investigated six bomb-related incidents since the Boston bombing. Three involved suspicious packages, including the one that shut down Dale Mabry Highway on Tuesday and another that caused a cruise ship terminal evacuation at the Port of Tampa last week.
Three others were phoned-in bomb threats, including the call that cleared out the Fifth Third Bank building.
The suspicious package found Tuesday was filled with garbage, McElroy said.
Tensions rose briefly after a bomb-sniffing police dog “alerted” on a scent in the package, which was spotted by a passer-by at Dale Mabry Highway and Santiago Street.
Police said the package, addressed to the Tampa Bay Times but with no return address or postage, wasn’t a threat. Investigators are trying to determine what chemical odor caused the dog to react.
The scene in South Tampa was similar to what happened at the Port of Tampa on Thursday, when bomb-sniffing dogs detected a suspicious odor coming from a pallet of liquor boxes about to be loaded onto a cruise ship.
The discovery prompted police to shut down Channelside Drive for more than four hours, evacuate the terminal, prevent passengers from boarding and call in bomb squads and robots.
Investigators found a small amount of magnesium nitrate hexahydrate on a piece of metal. The chemical can be used as an ingredient in explosives, but also is found in fireworks and fertilizers, authorities said.
McElroy said the precautions taken at the port and in South Tampa were necessary.
“Everybody is certainly on high alert,” she said. “It’s very rare when a canine alerts to something. We take these incidents very seriously.”