Two separate crashes involving seven vehicles on the Dan Ryan Expressway

Investigators are trying to figure out what led to an accident scene on the Dan Ryan Expressway near 95th Street early Sunday morning.

There were actually two separate crashes involving seven vehicles in all.

Some people were treated, but all injuries were minor.

Police are not calling it a chain-reaction crash, but they say it's possible the first crash triggered the second one.

The Dan Ryan is back open to traffic Sunday morning.