Huge back-up after 2 crashes on I-94by: updated: Friday, August 22, 2014 ‹ › CALHOUN COUNTY, Mich. (NEWSCHANNEL 3) - Traffic is getting back to normal on I-94 in Calhoun County after two crashes involving semi's shut down part of the road Friday morning for hours.Traffic was at a standstill for miles, with people getting out of their cars and standing on the highway after the chain reaction crashes that happened four miles apart.The first crash happened on westbound I-94 at Mile Marker 104. That's Michigan Avenue, right by Firekeepers Casino.A semi-truck tipped over on the left side of the highway.It took more than three hours for heavy machinery to get the truck upright.Traffic was backed up for more than four miles as a result of that crash, which caused another, more serious crash.This one was on westbound I-94 at Mile Marker 108 just past I-69.Two semi-trucks and a garbage truck were involved.Deputies tell us the two semis were stopped as a result of the other crash and the garbage truck slammed into them.Two people were seriously injured in the crash."It's a pretty serious accident and it's just tremendous damage. Any time you're dealing with heavy vehicles they definitely can create a massive amount of damage," said Det. Steve Hinkley of the Calhoun Co. Sheriff's Dept. We spoke with a woman who lives nearby. She heard the impact of the crash and says it's a dangerous area."I was standing in my hallway and I thought 'was that lightening?'" said Mary Findley. "And it shook my house, which is down the road from this area. And my heart breaks every time because there are so many accidents."Police tell us none of the injuries appear to be life threatening.They are still investigating the case of both crashes.