What does "he was there for" mean in this sentence?

I really don’t understand the usage or the meaning of “he was there for” in this sentence :

Tony shook his head, as though he couldn’t wrap his mind around events
he was there for, and partially responsible as well.

I understand the phrase “be there for somebody” means “support” somebody; but is it also ok to say “be there for events”?? or I just misunderstood it?

Here is the context:

Tony, the Iron Man, and the Cap fell out; Bruce tried to convince Tony to contact Cap，as Thanos is coming, they are facing the greatest danger in history.

Here is the sentence in the book:

“It’s not that easy,” Tony sheepishly admitted. Realizing, he looked
at Bruce again, a touch of shame entering his usually cocky attitude.
“God, we haven’t caught up in a spell, have we?”

“No.” Bruce tried to hide the feeling of betrayal from his voice.

Tony shook his head, as though he couldn’t wrap his mind around events
he was there for, and partially responsible as well. “The Avengers
broke up. Cap and I fell out hard. We’re not on speaking terms.”

“Tony, listen to me.” Bruce felt like he was now dealing with two kids
who had a schoolyard fight. The magnitude of what they faced was
beyond a falling-out between teammates. “Thor’s gone,” he stressed.
“Thanos is coming. It doesn’t matter who you’re talking to or not.”

The Avengers 3