Front Air Bag Sensor Control problems of the 2000 Mercury Villager

On June 8, 2002 I was driving down a major hwy in louisiana. I was driving 70 miles per hour which was the posted speed limit. A car clipped my front end and caused me to go off the highway into the grass. I don't know if my brakes were a problem because they are anti-lock so I'm not sure if this was suppose to happen along with the airbags but when I applied the brakes the van would not stop. I ended up back on the freeway across traffic still going in the same direction, and hit a metal guardrail head on that was located beside the concrete wall that holds up the bridge. The van then bounced off the wall, hit it again then turned around. This is all that I can remember. When my van hit the guard rail my head hit the steering wheel. The airbags on either side did not deploy. My husband hit the dashboard on the passenger side. I have pictures from the crash where the airbags did not even attempt to deploy, I spoke with robert smith at the dealership where the van was towed. He stated that by looking at the van because it has been declared a total loss he'd wished the airbags had deployed , but luckily we all walked away from the crash. He did state that there are several sensors and that they all have to register and hit has to be a head on crash. My comment was going 70 miles per hour and hitting a metal guard rail head on, how much head on do you need?.