All passengers were safely removed from the bus once the line was rendered safe. They were trapped for more than an hour.
"The power lines went down and hit the bus," said Jody McGinty, one of the passengers who was trapped. "It sounded like bombs going off. I thought we had gotten electrocuted."
One elderly man had to be transported to a hospital for heat exhaustion.
The bus travels between Lake Elsinore and Wildomar.
Several trees and utility poles were knocked down in the area by a passing storm Wednesday afternoon.
Storms in Lake Elsinore on Wednesday triggered power outages and knocked down trees.
"All of a sudden all the strong wind came and it started pouring down," said Daniel Alva, whose roof was damaged by the storm. "Stuff was just flying from all over."