Russia launched its largest drone and missile bombardment of Ukraine overnight into Wednesday, according to Ukrainian President Volodymyr Zelenskyy.

After deadly attacks and warnings from Ukraine and Israel’s drone strategies, the Pentagon is scrambling to adapt to a fast-moving threat.

Major General Thomas M. Suelzer with the Texas National Guard said a remotely piloted aircraft, or drone, was launched out of Houston Sunday to help with rescue and recovery. The MQ-9 Reaper is operated out of Houston and provides reconnaissance to the search and rescue teams.

The early attempt at drones in World War II saw the Army Air Forces convert B-17 bombers into remote-controlled flying bombs.

KYIV, Ukraine (AP) — Russia fired more than 100 drones at civilian areas of Ukraine overnight, authorities said Monday, as the Kremlin dismissed its transportation chief after a weekend of travel chaos when airports grounded hundreds of flights during the busy vacation season due to the threat of attacks from Kyiv.