Probably ran over FOD. Tires on commercial airplanes are typically not replaced until the tread depth is 1/32 of an inch deep. Sometimes they are not changed until the tread cord is showing. Then they are removed and sent to a shop to be retreaded. Blowouts are very uncommon. Most happen on landing if the antiskid fails. Not uncommon for a tire to last over a month with several landings a day.
On trucks 1/32 is allowed on drive and trailer tires, steer tires must have 1/16.
Drive and trailer tires can be retread twice, iirc. Steers can be retread, but can no longer be steers.