The Paul Lee Bus Safety Law was created after 19-year-old Paul Lee, a Whitter student who had severe autism, was left on a bus in the heat in September 2015. He was found dead hours later.
"I cannot believe that happened. How they left my son in the bus in the hot weather. So that tragedy happened to us, just I still cannot believe that," his mother, Eun Ha lee, said.
Lee could not verbally communicate and needed special care. The bill requires all state buses to have an alarm that sounds when the engine is turned off. The bus driver must then walk to the back of the bus, checking all the seats, before turning it off.
The family said they are still struggling with the loss of their son every day, but they hope a new awareness comes out of this tragedy and that the law saves other lives.
"It was like a big hug from heaven. So I'm so happy with (the decision) so it can protect the children in a safer way. My son did a good job - amazing. I'm so happy with that," Lee's mother said.
Some states, such as Arkansas and Wisconsin, already require school buses and child care vehicles over a certain passenger size to be equipped with child safety alarms.