GMC Safari Van Brake Line? on 1991 GMC Safari

I had just gotten on the highway and I heard a snap like something "fell off" the van, but there was nothing on the road. Then the brakes failed (locked up, couldn't depress them). Then the steering wheel also locked up. I pulled over on the shoulder and could barely stop the vehicle with the brakes as it would barely depress; I had to press very hard on the pedal.

Underneath the van, right below the radiator area, fluid was draining out (brake fluid probably) and a long string of rubber was hanging from a similar location under the van. The 2 ft of hanging rubber does not appear to be cylindrical like a tube, but the end on the ground appears tattered, like worn out rope at the end.

Any idea what happened? Broken brake line? Any issue with the brake master cylinder?

Thanks for any and all assistance!

Asked by for the 1991 GMC Safari
Possibly the drive belt snapped
1 more answer
The drive belt makes lots of sense. The fluid is probably coolant, it probably overheated without the fan. There wouldn't be brake fluid in the area of the radiator. These vans have a hydro-boost power brake system. It gives you power brakes and power steering. Without the belt you would loose the cooling fan, power steering, power brakes, the alternator, etc.