Around 250,000 gallons of raw sewage spilled into the Los Angeles River, forcing the closure of all Long Beach open coastal beaches, authorities announced late Thursday.

The spill occurred in Downey after equipment used by a Los Angeles County Sanitation District crew malfunctioned, “causing a temporary blockage in the sewer,” the City of Downey said.

The blockage overflowed into the street at Burns Avenue and Rives Avenue, and ultimately into the river.

“Although our staff worked to set up containment to prevent sewage from reaching receiving waters, we estimate that 250,000 gallons of sewage reached the Los Angeles River before our crews could fully contain the sewage that spilled into a local storm drain,” the City of Downey said.

News photographers said the smell in the area of I-710 at Imperial Highway near the L.A. River was “horrendous.”

All open coastal swimming areas in Long Beach, spanning roughly seven miles, were closed until further notice. A KTLA news crew, however, saw people still swimming and wading in the water, including a man who submerged his head.

“People shouldn’t swim in the water,” said Dr. Anissa Davis, Long Beach’s Health Officer. “Raw sewage contains various pathogens including bacteria, viruses and parasites, which can be ingested and cause illness.”

The most common illness caused by exposure to sewage is gastroenteritis, the symptoms of which include nausea, vomiting, and diarrhea, Davis said.

Other illnesses include skin, eye and ear infections.

Residents were urged to call the Water Hotline at 562-570-4199 or visit longbeach.gov/beachwaterquality for status updates.