A truck carrying laboratory monkeys overturned on a Mississippi interstate, prompting a massive search operation as three rhesus macaques remained at large in rural countryside.

The Jasper County Sheriff's Department reported that the truck was carrying 21 rhesus monkeys when it crashed Tuesday along Interstate 59 near Heidelberg, according to Newsweek. Officials initially believed only one monkey had escaped and been killed, but Tulane University experts who examined the scene later determined three monkeys were still missing.

Sheriff Randy Johnson said the monkeys were not infectious, despite early reports from the truck's occupants claiming they carried dangerous diseases. However, he maintained the animals were aggressive and needed to be "neutralized" if found by authorities conducting the ongoing search operation.

Initial Emergency Response And Recovery Efforts

Video footage from the crash site revealed several monkeys crawling through tall grass near the highway, with wooden crates labeled "live animals" scattered across the roadside. The chaotic scene prompted immediate mobilization of law enforcement and specialized animal recovery teams to contain the situation.

By Wednesday morning, officers and workers wearing protective clothing were systematically combing the rural area in search of the missing animals. The remaining 18 monkeys were successfully recovered and transported safely back to Louisiana, according to official reports.

The search operation expanded across the countryside near Heidelberg, located roughly 100 miles southeast of Jackson. Authorities established a perimeter and deployed multiple teams to track down the escaped primates before they could venture further into populated areas.

Conflicting Reports About Animal Safety

The truck driver initially told local law enforcement that the monkeys were dangerous and posed a threat to humans, leading to early confusion about public safety protocols. "We took the appropriate actions after being given that information from the person transporting the monkeys," the Jasper County Sheriff's Department stated in a Facebook post Tuesday.

However, Tulane University later contradicted these claims, confirming that the monkeys had recently been tested and were pathogen-free. The university clarified that while it did not own or transport the animals, it dispatched veterinarians and researchers from its National Primate Research Center to assist in recovery efforts.

The conflicting information created initial panic among local residents and complicated the emergency response. Tulane's National Primate Research Center, located about 40 miles north of New Orleans, routinely houses primates used in scientific and biomedical studies and confirmed the animals posed no infectious disease risk.

Previous Incidents And Research Context

This crash follows a similar incident last year in South Carolina, when 43 rhesus macaques escaped from a medical research breeding facility after an employee failed to properly secure an enclosure. Workers from the Alpha Genesis facility in Yemassee had to set traps to recapture those escaped monkeys.

Rhesus monkeys, which typically weigh around 16 pounds, are among the most widely used primates in medical research worldwide. Their genetic similarity to humans makes them valuable subjects for studying diseases and testing potential treatments.

The frequency of such incidents has raised questions about transport protocols and security measures for research animals. These primates are regularly moved between facilities for various research purposes, creating multiple opportunities for escape scenarios.

Lessons to Learn

1. Personal Safety Comes First: In events involving escaped or aggressive animals, public safety officials advise against trying to interact with or capture them. Even animals that appear harmless can become dangerous under stress. Stay at a safe distance and report the sighting immediately.

2. Be Aware of Warning Signs: In emergencies following highway accidents — particularly those marked by biohazard or animal warning labels — people in the area should exercise caution and heed all instructions from law enforcement or emergency responders. Being observant can prevent risky situations.

3. Understand That Accidents Can Happen Anywhere: Despite the best efforts of drivers, scientists, and transport specialists, accidents do occur. It’s important to remember that no one deserves to be blamed when unexpected events unfold. Remaining informed can help you react appropriately in future scenarios.

Why This Story Matters

This story highlights the often-overlooked risks involved in transporting live animals for scientific use — particularly when unexpected accidents occur along public roadways. It reminds the public that safety protocols must extend beyond the labs where research is conducted. The escape of three monkeys also underlines how public agencies and academic institutions must collaborate swiftly in times of crisis.

Conclusion

On Oct. 28, 2025, a transport truck carrying 21 Rhesus monkeys crashed along Interstate 59 near Heidelberg, Mississippi. While most of the animals were safely recovered, three primates remain missing, prompting a widespread search by state and local agencies. Though officials stress the monkeys are not carrying infectious diseases, their aggressive behavior has made the situation more urgent. Tulane University experts are now assisting on-site, and the Mississippi Highway Patrol continues to investigate the cause of the crash. As the search continues, the public has been asked to stay alert and avoid direct contact with the animals.