Two Americans were arrested at one of the most historic ruins in the world for carving their initials on the walls of the structure.

The Daily Mail reported that Italian police charged two female tourists from California with “aggravated damage on building of historical and artistic interest” after they etched eight-inch high letters into the wall of the Colosseum in Rome and then posed together for a selfie.

Reportedly, the two women had broken away from their tour group to carve the defacing graffiti, while other tourists observed them in the act and alerted security.

After being apprehended, the two women insisted that they didn’t realize what they did was so damaging. They told Captain Lorenzo Iacobone and Piazza Dante that they were sorry for their deeds. “We apologize for what we did. We regret it but we did not imagine it was something so serious.  We’ll remember for a lifetime.”

Unfortunately, the thoughtless Californians are not the only ones defacing the two thousand-plus-year-old edifice. Due to a lack of adequate security funds, defacement to the structure has become common place.

According to the Special Superintendency for the Archaeological Heritage of Rome, “The building was, and still is today, a show in itself. In fact, it is the largest amphitheatre not only in the city of Rome but in the world, able to offer stunning sceneries as well as services for spectators.”