At least 15 people were killed and nearly 40 injured Sunday in a bus crash near the Brazilian colonial town of Paraty, according to reports. Police are reportedly trying to determine the cause of the crash.

The bus was traveling to Trinade, a popular beach about 19 miles south of Paraty, when the accident took place, the Associated Press reported. The stretch between Paraty and Trinade, which is often locally called “God Help Me Hill,” is an accident-prone area, according to the BBC. Roads were reportedly busy this weekend as Monday marks the country’s Independence Day -- a national holiday.

The news report included footage of the bus, overturned on the shoulder of the road. The injured have been taken to local hospitals, the report said.

A video showing the overturned bus was reportedly published by Globo television network’s online edition.

Paraty, a Portuguese-era colonial town with a population of around 40,000, is between Brazil's two most populous states, Rio de Janeiro and Sao Paulo.