[Scan-DC] River Road rescue activity - anybody catch this?

[Spaceboy]

I was driving on River Road this morning around 9:30 on my way to see 
relatives near Seneca and the road was blocked at the intersection with 
Swains Lock Road by a fire truck and several ambulances. A MSP medevac 
helicopter was there as well. I was talking to some other people who were 
stuck there and  they thought there may have been an accident at the 
nearby WSSC water filtration plant, but judging from the location it 
could have also been a  river rescue operation. Of course, I didn't have 
my scanner with me at the time, and was in a hurry so I couldn't wait 
around very long to watch. Does anybody know anything about what happened? 

Thanks, Jesse