A gunshot was reported at Grand Forks Air Force Base in North Dakota on Wednesday, prompting a lockdown of the military base, officials and witnesses say. There were no immediate reports of injuries. The incident happened at around 1 p.m. on Wednesday when a lockdown message was issued, warning people about an “Active Shooter situation” at the base. “All base personnel implement LOCKDOWN procedures and immediately take shelter,” the message said. Lea Greene, a spokesperson for Grand Forks Air Force Base, said the lockdown was issued after security forces received a report about a single gunsho…