LOS ANGELES (AP) — Los Angeles school officials say 71 iPads, including 69 from a single campus, went missing last year as the district tested a program intended to equip every student with one of the Apple tablets.

The Los Angeles Times reports the lost devices are among iPads used in a13-school trial run.

Officials tell the newspaper that new security measures are being implemented to keep track of the tablets, which cost nearly $700 apiece and were intended to be sent home with students.

This week the district banned home use of the iPads after nearly 300 students figured out how to alter the security settings so they could surf the Web and access social media sites.

Officials are looking for ways to make sure students use the devices for school work only.

About 14,000 iPads have been distributed so far.