Thursday morning, Brett Davidoff says he was stuck in typical 610 Loop traffic heading north when he saw an HISD bus leaving a thick trail of smoke in the southbound lands.
"In the cloud of smoke, there were a lot of cars that came to a stop and put their hazards on," he said.
He recorded a brief video of the bus and said it created a dangerous problem for drivers who couldn't see the road in front of them.
"It's definitely very concerning," Davidoff said.
After finally tracking down the smoking bus, an HISD spokeswoman told ABC13 no one was on board except the driver. She said a radiator problem created the cloud of smoke.
But, the issue is becoming even more concerning after an incident involving another HISD bus that happened on Wednesday, less than 24 hours earlier.
A bus burst into flames near West Bellfort and South Post Oak. Four people were on board when this emergency started; one of them was a student with special needs in a wheel chair. They were able to escape unharmed. The cause of that fire is still not clear, according to HISD.
READ MORE: HISD bus carrying student with special needs catches fire
These incidents are making people question HISD's bus fleet safety conditions.
"You would hope, as a district, they would have enough funds to maintain and upkeep their bus fleet, because there's thousands of kids riding them every day," Davidoff said.
There are about 36,000 students who ride those buses each day, according to HISD's website, and about a thousand buses carry these children.
ABC13 anchor Steven Romo asked HISD about the bus fleet's safety inspections and what methods are being used to check the buses as well as how often they're inspected. An HISD spokeswoman said that information was not immediately available.
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