The ignition took place at about 4:20 local time and caused a large pressure wave and fireball that damaged the launch pad. Although an official cause has not been detailed, speculation suggests the fire may have been prompted by a potential liquid leak.
Video of the incident showed thick black smoke emitting from the bottom of the launch tower following the test.
SpaceX founder Elon Musk said via Twitter that the ignition test was planned but later deleted the tweet. In response to another user, he commented that the incident was "not good," and that officials were looking into the damages.
The Starship is a fully reusable two‑stage‑to‑orbit super heavy‑lift launch vehicle under development by Musk's SpaceX. Musk plans to use this spacecraft to establish permanent bases on the moon and Mars. The booster stage is powered by 33 Raptor engines.
In June, Musk said the Starship spacecraft could be ready for a series of orbital flight tests as soon as July.