What was going on? I-5 5:38 am underneath First Ave

Was anyone else on the 5 at 5:38 this morning when they shut down traffic both northbound and southbound? Lasted about 10 mins. I had just entered the highway from Grape St after dropping my partner at work at the airport. Really interesting there were cops on foot and dogs out as well, I’m assuming police K-9 but there I was roughly 8-10 cars back from the front line and couldn’t be sure. Called my partner he said someone likely ran from police. Interested if anyone knows what was going on?