No one was injured, but there were some tense moments when the Megabus and semi got pushed up against the guardrail.
The Megabus, which was headed from Detroit to Chicago, slid on the ramp of the Indiana Toll Road and struck the guardrail as it tried to pass the stalled semi. Passengers say it nearly went over.
Passenger John Covington was on the top deck of the double-decker Megabus when the incident occurred.
"We get to the overpass and we just start sliding. The entire bus slides to the left up against the rail," Covington said.
"We had people up top that thought we were going to tilt over because we were so close to the rail and they wouldn't let anybody off the bus," Dorothy Lewis said. "I felt safer off the bus, just in case. I don't know how sturdy that rail is, you know, to hold that big bus."
Originally told they should stay on the Megabus for their own safety, passengers were eventually evacuated as officials moved the bus from its precarious situation. Another concern- the gas tank on the tractor trailer was wedged up against the guardrail and emergency responders worried it could explode.
"We're all, I think, a bit shaken. I had a plane to catch at 8:30 this morning out of O'Hare. I'm not concerned about that. I'd rather get there late than to not get there at all," Covington said.
The Megabus was eventually driven off the ramp, the passengers got back on it since the vehicle didn't suffer any heavy damage, and then they drove away.
The semi followed without any incident.
Megabus released a statement saying the company is "aware that an incident has occurred near Lake Station, Indiana on the Indiana Toll Road (Interstate 90). We are currently working with local officials to gather details of the incident. Safety is megabus.com's number one priority."
The Megabus incident was just one of many involving icy roads across the area. The sudden drop in temperatures and snow left some drivers in disbelief.
"The bills gotta get paid. But this is incredible. It's unbelievable. I just had my shorts on Friday," Andre Williams, postal worker, said.
"I didn't expect to be cleaning up my car today. It's Easter Day for my granddaughter, so she's dressed like it's April," Theresa Sanchez said.
Tom Hopkins, 81, said this is the first time he remembers shoveling snow this late in April.
"I've been tired of it since before it started. I'm an old man to do this...but I get by," Hopkins said.