Divers searching for about three hours found no bodies in Tempe Town Lake after a pickup truck went in early Wednesday.
Mike Reichling, Tempe fire spokesman, said divers searched the cab and bed of the truck and 100-foot perimeter of the pitch-black bottom.
"It's black, real, real dark, you can't see your hand in front of your face," Reichling said.
He said there is still a slim chance a body could float to the surface.
Sgt. Dan Masters, Tempe police spokesman, said police believe the truck was a 1979 Chevrolet that was stolen about 4 a.m. from a business.
The truck was submerged at an approximately 40-foot drop near the Grigio Luxury Condominiums on the north bank of the lake, east of the Rural Road bridge.
Masters said investigators believed the truck was driven into the lake at a high rate of speed, and someone may have been ejected because it barrelled over two concrete walls above the lake.
Reichling said the fire department was called about 9 a.m. after a fisherman reported seeing the truck go into the lake.
The fisherman said he believed there were two people inside.