A digital traffic sign in Houston was apparently hacked to display apocalyptic messages warning of a climate catastrophe.

The sign, located off Waugh Drive and Allen Parkway, was spotted early Wednesday flashing messages including "Global warming at work," "Warning: Hurricane Human," "Triassic weather ahead" and "We are the asteroid."

It was unclear how the hacker gained access to the sign.

Signs along a North Carolina highway were hacked in a similar fashion in May 2018, when drivers noticed the signs were displaying messages warning of "idiots on bikes" ahead of the local Ironman competition.

Another sign in Pennsylvania was hacked that same month with a rude message instructing Delaware County to perform a lewd act with a sex organ.