The windows were smashed on about 21 school buses.
A police officer discovered the damage just before 7:15 p.m. Sunday at the bus lot located on the 3800 block of Woodhaven Road in Northeast Philadelphia.
This is just the latest hit to the cash-strapped district.
School District Spokesperson Fernando Gallard explains, "We are actually self-insured. Thousands of dollars, basically. Damage right now I think could be upwards of 20, 30,000 dollars. We are still looking at the numbers."
A school police officer stood by the entrance to the lot Monday morning. District officials say there is security on site, but wouldn't go into specifics as to who was on duty this weekend.
There were some delays this morning, but since a lot of the fleet is contracted out, their partners were able to cover many of the routes.
Now the focus is on repairs.
"The good news is it is glass that we can repair. The bad news is thousands of dollars that we now have to put on our buses that we could use in the classroom," said Gallard.
It could be a couple days until all the buses are fixed, but most should be back on the street by Tuesday.
Police are searching for the people responsible.