Pax Jolie-Pitt’s electric bike crash was so intense that the people who rushed over first thought he might have died right there on the spot … TMZ has learned.

Eyewitnesses tell us … the people living on the L.A. street where Pax crashed his BMX-style e-bike into a car Monday thought he was a goner when they saw him lying still on the ground — that is, until he regained consciousness when paramedics arrived at the scene.

We’re told Pax’s bike looked fine and didn’t show any obvious signs of damage from the impact … but we’re told PJP himself was out cold, and had folks incredibly worried.

BTW, our sources say the area this happened in isn’t far from where Angie herself lives.

Anyway … all this new info lines up with our initial report that responders were worried about a possible brain bleed — especially since he’d been riding without a helmet. We also know Pax ended up staying overnight in the hospital.

We broke the news … Pax — Angelina Jolie and Brad Pitt’s 4th kid — was also dealing with hip pain along with his head injury, and was rushed by an ambulance for treatment.

As of Tuesday, sources with direct knowledge tell us he’s in stable condition — and that his mom is by his side.

Pax has been seen cruising around L.A. on his bike without a helmet — but after this close call, he might want to consider getting some protective gear … these streets are dangerous.