At the Port of Los Angeles and Long Beach, police increased security procedures by doing critical site checks of property around the port complex as well as coordinating with multiple local and federal law enforcement officers.
The explosions also spurred a review of security at upcoming sporting events. British police said they were re-examining plans for Sunday's London Marathon — the next major international marathon.
The San Francisco Police Department was also rethinking security for the upcoming San Francisco Marathon in June and the Bay to Breakers race in May. In Indianapolis, authorities were reviewing security for next month's 500 Festival Mini-Marathon, while in Nashville, increased security precautions were being considered for the Country Music Marathon on April 27. Stepped up security was also put in place for this weekend's marathon in Lansing, Mich.
Security was heightened for a number of sporting events Monday night, including the Dodgers-Padres game in Los Angeles and the Nationals-Marlins game in Miami. But Major League Baseball said no changes were planned to ceremonies at ballparks around the country to commemorate Jackie Robinson Day, though several teams informed the league they planned moments of silence.
In Miami, a police officer with a dog patrolled near a ballpark entrance — an unusual sight at the venue — two hours before the game. In Tennessee, hockey fans watching the Nashville Predators play the Vancouver Canucks were seeing "more visible presence around the building," team spokesman Kevin Wilson said.