Traffic on Interstate 55 screeched to a halt Wednesday after two back-to-back crashes within a half-mile of each other shortly before 8 p.m., officials said.

Plainfield Deputy Fire Chief Jon Stratton said the first call came in around 7:30 p.m. after a four-car crash on southbound I-55 just past Route 126 at mile marker 260.

“It sounded like somebody swerved, and it just started a chain reaction,” he said.

Six people refused treatment following the accident, and three were transported to area hospitals with non-life-threatening injuries, according to Stratton.

Less than half an hour later, a second crash just half a mile down the road involved a semi-truck and two other vehicles in a similar chain reaction accident, Stratton s aid.

One person was transported to a hospital with non-life-threatening injuries, and three refused treatment, he said.

The accidents brought traffic on I-55 to a standstill.

“The vehicles were in the southbound lanes, there was a vehicle in a ditch,” Stratton said, adding several Good Samaritans also stopped to offer assistance. “There were people everywhere.”

A spokesman for Illinois State Police District 5 said no additional information on either of the I-55 crashes was immediately available Wednesday night.

Plainfield firefighters responded to a report of a third crash that came in around 9:50 p.m., Stratton said.

This time, a car was struck as it crossed Route 59 in front of Menards in the 13400 block of Route 59, Stratton said.

“A vehicle was T-boned and rolled over on its side,” near the entrance to Menards, he said, while the other car ended up in a grassy area off Route 59.

The two drivers refused medical treatment in that crash, Stratton said. He said Plainfield police are investigating the crash.