Two women were seriously injured Thursday afternoon during a head-on collision in Ridgefield. A white Toyota minivan was southbound on Northeast Delfel road near Northeast 199th Street when, firefighters believe, the driver suffered a medical emergency. The van went into the northbound traffic lane and hit a Honda sedan, said Battalion Chief Tim Dawdy, spokesman for Clark County Fire & Rescue. The sedan left the roadway, coming to rest in the brush bordering Interstate 5, while the minivan kept rolling down the wrong side of the road. Joe Ploium, the driver of an oncoming pickup truck, saw the accident occur. He slowed down, giving the minivan some time to slow down, and stopped the vehicle with the front of his truckThe minivan could have otherwise kept going and hit someone else or gone off the roadway, Dawdy said, lauding the driver’s quick-thinking actions.The drivers of the minivan and sedan, both women, were transported by ambulance to PeaceHealth Southwest Medical Center.