HEIDELBERG, Miss. – What began as a chaotic escape of research primates from an overturned truck on Interstate 59 evolved into a revised tally Tuesday evening, with officials now reporting three Rhesus monkeys still at large rather than one, following a more accurate count by Tulane University experts.
The incident unfolded around 1:30 p.m. near mile marker 117 north of Heidelberg, when a semitrailer transporting the monkeys from Tulane University’s National Primate Research Center in New Orleans to a testing facility in Florida lost control and flipped. The 21 rhesus macaques—each weighing about 16 pounds with brown fur, red faces, and ears—broke free from damaged crates, scattering into nearby woods and prompting an urgent multi-agency response.
Jasper County Sheriff’s Department initially posted on Facebook around midday that five escaped monkeys had been captured and euthanized on site as a precaution, with all but one of the rest accounted for and destroyed. The alert warned residents that the animals were “aggressive to humans” and required personal protective equipment due to potential risks from hepatitis C, herpes, and COVID-19, based on information relayed by the truck driver. “Do not approach the monkeys if you see one. Call 911,” the post urged, as deputies coordinated with the Mississippi Department of Wildlife, Fisheries, and Parks and an animal disposal company.
By late afternoon, the sheriff’s office updated that search teams, using thermal imaging and ground patrols, had neutralized 18 of the escapees, leaving one elusive primate unaccounted for. The driver, who sustained no injuries, was evaluated at the scene.
However, around 7 p.m., Tulane officials arrived and accessed the wrecked trailer for a precise inventory, revealing that the initial escape count was off. The Jasper County Sheriff’s Department then revised its statement: “There are 3 monkeys still on the loose after the officials from Tulane were able to get inside the truck and get a correct count.” The university’s team, including animal care experts, is now assisting with recapture efforts using tranquilizers, emphasizing non-lethal methods where possible.
Tulane University clarified in a statement that the primates “have not been exposed to any infectious agent” and had received recent checkups confirming they were pathogen-free. “The non-human primates were NOT being transported by Tulane, but we are actively collaborating with local authorities and sending a team of animal care experts to assist as needed,” spokesperson Andrew Yawn said. The university noted the monkeys are provided to other research organizations to advance scientific discovery and stressed that the initial health warnings stemmed from the driver’s report.
Sheriff’s officials acknowledged the discrepancy, stating they “took appropriate actions after being given that information” to protect public safety. No human injuries or contacts with the monkeys have been reported, and health risks to the community remain low, according to state wildlife officials.
The crash caused a four-hour closure of northbound I-59 lanes, now reopened, with cleanup ongoing. Video footage shared by authorities shows crumpled wooden crates labeled “live animals” amid tall grass, and at least one monkey visible scrambling away.
The expanded search, now targeting three animals, continues into wooded areas with aerial support. Residents near Heidelberg are advised to stay vigilant and report sightings to 911. As the operation unfolds, the incident highlights the complexities of transporting lab animals, drawing criticism from groups like PETA, which called it a “clear example of the risks of the greedy monkey experimentation industry.”
Investigators are probing the wreck’s cause, with no other vehicles involved and clear weather conditions. Tulane and local agencies plan a joint briefing Wednesday to update on recapture progress and biohazard protocols.
