Palestinians in besieged Gaza crowded into hospitals and schools on Monday, seeking shelter and running low on food and water. More than a million people have fled their homes ahead of an expected Israeli ground invasion aimed at destroying Hamas after its fighters rampaged through southern Israel.

As the enclave’s food, water and medicine supplies dwindled, all eyes were on the Rafah crossing between Gaza and Egypt, where trucks carrying badly needed aid have been waiting for days as mediators press for a cease-fire that would allow them enter Gaza and allow foreigners to leave. Rafah, Gaza’s only connection to Egypt, was shut down nearly a week ago because of Israeli airstrikes.

Hundreds of thousands of Palestinians sheltering in U.N. facilities are on less than 1 liter (1 quart) of water per day. Hospitals warn they are on the verge of collapse, with emergency generators that power machines like ventilators and incubators down to about one day of fuel and supplies of medicine almost exhausted.

The Gaza Health Ministry said 2,750 Palestinians have been killed and 9,700 wounded since the fighting erupted, more than in the 2014 Gaza war, which lasted over six weeks. That makes this the deadliest of the five Gaza wars for both sides.

More than 1,400 Israelis have died, the vast majority civilians killed in Hamas’ Oct. 7 assault. The Israeli military said Monday that at least 199 hostages were taken back in Gaza, higher than previous estimates. The military did not specify whether that number includes foreigners.

Israeli airstrikes have pulverized entire neighborhoods as Palestinian militants continue to fire rockets into Israel. Israel is widely expected to launch a ground offensive in order to kill Hamas leaders, recover captives and destroy the group’s military infrastructure, much of which is in residential areas.

Street-by-street fighting would likely cause mounting casualties on both sides.