To take a wider view of the area:
This area is like a perfect storm of danger. You have cars coming off the northbound Las Olas exit cutting across 3 lanes of traffic to get into the turn lane to take Broward Blvd North. And then you get cars coming out of the tunnel blindly cutting across to either make a fast right, or turn turn right onto Broward Blvd. It's a total disaster. I can't tell you how many times I've had someone dart in front of me trying to make that right.
In this case it looks like someone was cutting across 3 lanes of traffic and caused a chain reaction type accident.
At 7:45 they were still clearing the rubble:
I wonder if a bottomless Sunday Brunch was involved?